A few days after the beginning of the fast I noticed some other singular bodies. They were irregular in shape with the general appearance of white blood corpuscles, were faintly granular, and often exceeded 1 of an inch in diameter. Sometimes they contained dark particles embedded in their substance as though fragments of red blood corpuscles. They became less and less in number with the increase of the first described bodies but never entirely absent.

I noticed some bodies which were stellate in shape, with rays thick at the base, but passing off into long slender filaments which connected with the fibrine threads. They varied in size, but usually were smaller than a white blood corpuscle. They were exceedingly pale and difficult to see, but they had a distinct body, made up of something more than the crossing of fine threads, though appearances something like them were seen which were merely the crossing of threads. These bodies would take a distinct stain from carmine.

There were also other bodies which it is difficult to classify. Several times I saw large colorless disks, sometimes more than τσοσ of an inch across. In freshly drawn blood they had a raised rim either smooth or more often slightly fissured at intervals. After a time the fissures extended in every direction dividing the body into a great number of angular pieces. The pieces appeared to be attached to one another, though I am not quite positive about it. These bodies were seen occasionally throughout the whole of the fast.

Small colorless bodies were occasionally seen after the first two or three weeks which resembled oil drops. I did not test these chemically, but I do not think they were oil. They had a refractive power which differed from that of oil; they could not be made to change their shape by pressure as oil could, and under no circumstances would they coalesce. There were some go to Todoo of an inch in diameter though variable. They would not stain with carmine. Other bodies were seen which looked like these only somewhat fainter. They were often collected in masses. They were the palest and most transparent structures that I saw in the blood. I have tried again and again to trace them with the camera lucida, but usually failed, the slight impairment of definition of the prism being sufficient to render them invisible. Often I lost them in looking over a field, and was unable to find

them again. They were present after their first appearance during the whole of the fast.

After about the fourth week of the fast I occasionally saw a pale globular body, like a sac with a piece cut out of the top. These bodies varied from about ʊʊ to oʊʊ of an inch in diameter. The suspicion has crossed my mind that they were the discolorized remains of a red blood corpuscle and that their progenitors were the pale corpuscles with the thickened rim, but I am by no means

sure.

Very often, even early in the fast, I saw bodies of the same color as the red corpuscles, embedded in the substance of a granular white corpuscle. In one instance I saw an unmistakable small red corpuscle with biconcave sides occupying this position.

SOME PHENOMENA IN THE CONJUGATION OF ACTINOPHRYS SOL. By J. D. Cox, of Cincinnati, Ohio.

In the latter part of last winter the opportunity occurred of making some consecutive observations upon this rhizopod in an infusion in which it appeared in considerable numbers, and some of the phenomena are so curious as to seem worthy of record.

These phenomena more particularly relate to the conjugation of the animalcule; but before describing them, I wish to note one or two points, which have reference only to the general form.

Professor Leidy, in his late work on the Rhizopods, gives his opinion that the rays of the Actinophrys are simply gelatinous pseudopodia of the same substance as the body, and without any solidified skeleton. The evidence for this he finds in the bending of the rays, under the force of a current, like grass in a rivulet. I have frequently observed this bending, but when it occurs under the influence of a current in the water, or of a passing animalcule of another kind, it has been greatest near the tips of the rays, and seemed consistent with a more or less perfect solidity in the parts

near the spherical body. But, what seemed conclusive, I have noted instances in which, by the rush of a Daphnia against the Actinophrys, the greater mass and impetus of the crustacean have broken the rays near their base, leaving them at right angles to their normal direction.

Again, when the Actinophrys passes into a condition, to which I shall refer a little further on, and which I have described as the opaline, the rays, in some instances, show a marked appearance of being dissolved and not simply absorbed or retracted. In some cases, when the animalcule suddenly collapsed, the rays were left as granulated remains of what they were, dissolving in the water separate from the mass of the body, much as if they were spicules of crystal-sugar or some substance of similar solubility.

By this, I do not mean that the ray was altogether of this character, for the gelatinous covering was also made manifest: first, by a rapid retraction, or current, on its surface, by which the more minute objects of its prey were drawn toward the body of the animalcule, and second by a similar outward motion by which the ejecta were carried away from the body.

When, in passing into the opaline condition, the animalcule becomes more transparent, a ring is seen near its centre, which does not correspond to the ordinary appearance of a nucleus, as seen in the infusoria, but has more the appearance of a small inner sphere, such as is seen in the endoskeleton of some of the polycystinæ, and the rays appear to reach through the sarcode of the outer body and to connect with this. I will not speak of this as proved, for the translucence of the animalcule never becomes transparence, and definite assertion would be rash. I will only say that so many phenomena point to the existence of an endoskeleton consisting of two concentric reticulated spheres with rays, partially solidified, but soluble, that I accept this as the probable anatomy of the creature.

The extent to which solidification has gone, and the degree in which it is limited, seem to me to be indicated by the movements of the rays near the contractile vesicle when this expands and collapses. As the vesicle grows large like a great blister on the side of the animalcule, the rays on either side slowly widen their angle, and on the collapse they quickly approach each other, retaining the stiff, rodlike character, and their true line of projection from the centre of the spherical mass.

It has sometimes been stated that the rays of Actinophrys cross

each other and grasp the prey; the movement being figured as if the rays were analogous to the spines of Echinus and movable from the surface of the body. I have looked for something of this sort with great patience, and have seen the animalcule capture living things, times almost numberless, but have never seen anything like the process described. The radial swinging of the rays when the contractile vesicle collapses is the nearest approach to it, and this, in the case of two Actinophryes in conjugation, will, when the contractile vesicle is near the junction of the two bodies, cause the rays of the two to cross each other on that side. In the capture of prey, however, the process, in all the cases I have observed, is the following:

If the captured object is minute when compared with the captor, its motion is instantly arrested when it comes in contact with one of the rays. In a moment it slides inward toward the body, when a glairy and true amoeboid pseudopod is extended from the Actinophrys, irregular in form, but approximately funnel-shaped. This encloses the prey as in a capsule, which is then slowly drawn into the body of the captor, which assumes its regular outline. In some cases the food is apparently found distasteful, and is ejected again before being completely swallowed.

If the captured object is large, as a rotifer or a vorticella, the process is different. A vorticella will be enveloped by a large capsule, often larger than the body of the Actinophrys itself. In this extemporized stomach the food will be seen as a granulated, spherical mass, surrounded by the transparent capsule till digestion is completed, when the ejecta will pass out through the capsule, and the Actinophrys will resume its usual form. During the process it will have the general outline of the double form, as seen in conjugation, except that the rays will be seen only on one of the lobes, the other looking like a large, hyaline cell of equal size, but an excrescence on the animalcule.

In the case of carapaced rotifers, or large diatoms, the prey is more completely received into the body of the animal; but this has been so well figured in the ordinary books of reference, that I will not delay upon it. The point I desire especially to note is that in all these processes I have detected no movement of the rays, except such as were plainly mechanical and fully accounted for by the movements of the body in which they were planted. They, together with any connected endoskeleton which may exist,

are forced aside to make room for a diatom, etc., but I could observe nothing akin to spontaneous or voluntary movement.

The powerful stinging or benumbing effect of the rays of Actinophrys was exhibited in cases like the following. A Rotifer vulgaris, moving across the slide by doubling itself like a measuring worm, came in contact with the animalcule and, being evidently hurt, made violent efforts to get away. In these, the hinder part of the body seemed to have lost its power to take hold, and while the general activity of the body was convulsively increased rather than lessened, its tail constantly slipped back and a rapid series of doublings of the body gave it no headway. If it happened to get beyond the rays, it recovered its normal motions in a few moments. A Chaetonotus larus, swimming with its peculiarly strong and graceful motion, struck the rays, and the hinder half of the body became instantly limp and helpless, being utterly without power of motion. The rest of the body seemed strong as usual and kept up the most violent contortions. In this case, also, if the animalcule got away, its powers were restored in a few moments. Another very striking instance was that of the Trachelocerca olor. Swimming with its enormously long and swan-like neck extended, it struck one of the rays near the head. The head and part of the neck shrunk like wax melted in a flame, so complete and instantaneous were the shrivelling and loss of form. Cases of similar kinds were constantly occurring, and as the animalcules named are usually larger than the Actinophrys, the phenomena impress the observer with the extraordinary power exerted.

CONJUGATION.

The phenomena of conjugation may be considered either as to the exterior form or as to the results. First, as to form. Two individuals approach each other by a slow, sailing motion, as if merely drifting. Sometimes this continues till, the rays having crossed each other, the bodies come in contact and coalesce by the same imperceptibly progressive movement. At other times amoeboid pseudopodia are put forth before the contact, and one or more narrow necks connect the two spheres while they are yet separated from each other by one-sixth their diameter.

Usually the union proceeds through a dumb-bell shape till the diameter of the connecting part is about two-thirds that of the lobes. In a period varying from a quarter of an hour to several hours the separation begins, the process being now reversed, the