LIVING MATTER IN " PBOTOPLASM" 39 



often the appearance is presented of a single granule surrounded by wreaths 

 of other granules, all the latter being united, by means of radiating conical 

 threads, both to the central granule and to each other. Such small, wheel- 

 like bodies may arise in different places in the protoplasmic body during its 

 changes of shape. Besides the grayish-yellow granules, there are numerous 

 others of a more yellow color and of a greater refracting power, identical with 

 that of fat-granules. Experience shows that such fat-granules are more 

 numerous in the latter part of the breeding season of the oyster viz., in 

 July and August. Many of these fat-granules are connected by means of 

 delicate threads with the neighboring protoplasmic granules. 



During the changes of shape of the blood-corpuscle, round spaces often 

 appear in the protoplasmic bodies, the so-called vacuoles. These vacuoles 

 vary greatly in size ; they are filled with the light, structureless fluid sub- 

 stance which we see within and without the meshes of the net-work. In the 

 fluid of the vacuoles sometimes there are granules floating about. Each 

 vacuole is surrounded by an extremely thin grayish-yellow layer, which is 

 always in union, by means of delicate threads, with the neighboring granules 

 of the protoplasm. Sometimes several vacuoles arise within the corpuscle, 

 and are separated from each other by a continuous layer, like the shells of a 

 nucleus, and these shells give the appearance of a frame-work. The same 

 appearance of vacuoles, though on a considerably smaller scale, I have 

 repeatedly observed also on nuclei originally homogeneous and structureless- 

 looking. 



A continuous, though extremely thin, layer can be seen on the periphery 

 of and closing in the protoplasmic body. The outer surface of this layer looks 

 smooth, while its inner surface is in connection with the neighboring granules 

 by means of delicate threads. 



While we watch a blood-corpuscle of the oyster at the common tempera- 

 ture of the room, continuous changes of its shape are visible, as mentioned 

 above. At the same time, changes of the net-work within take place. Tem- 

 porarily, the granules seem grouped together and the meshes considerably nar- 

 rowed ; opposite to such a group of closely packed granules flaps bulge out from 

 the periphery of the protoplasmic body. Within a flap there is faintly visible 

 a net-work only at the beginning of its protrusion ; very soon this net-work is 

 completely lost to sight, and the flap looks homogeneous, and apparently 

 structureless. At other times, delicate narrow hyaline offshoots are projected 

 from the periphery of the blood-corpuscle, varying in number, and sometimes 

 considerably surpassing in length the diameter of the protoplasmic body. 

 These so-called false legs (pseudopodia), as a rule, look homogeneous, and 

 run either in a straight direction or are curved and repeatedly bent. They 

 are being projected and withdrawn frequently during the changes of shape of 

 the corpuscle ; sometimes they are thrown out so regularly, and in so great a 

 number, that the corpuscle assumes a beautiful star-shape, the central body 

 at this time being considerably decreased in size and its granules closely 

 packed together. The offshoots may also be irregular, and the blood- 

 corpuscle may take on a considerably elongated, irregularly angular, and 

 branching shape. On the thicker parts of the offshoots the net-like 

 structure of the protoplasm is to be seen, while their ends always look 

 hyaline and structureless. 



During the changes of shape, sometimes a number of granules melt 

 together, thus producing the appearance of a temporary nucleus; such a 



