Studies ill Cnistaeeaii Spermatogenesis, 467 



is formed in the interior, and at the distal extremity an intensely 

 staining body is conspicuous. (Figs. Hi, 26-27.) The exact man- 

 ner of formation of the inner tube is a little obscure. Koltzoft' (1906) 

 believes that the body (x) takes part in the process. Fig. Hi, 26 might 

 lend itself to such an interpretation. During the formation of the 

 tube only a portion of the body (x) stains brilliantly; the remainder 

 apparently streams towards the centre of the capsule to meet that 

 portion of the tul)e which is projecting from the proximal end of the 

 capsule. Upon completion of the tube, however, the entire body 

 stains deeply black with hsematoxylin and becomes constricted into 

 two unequal parts. (Fig. Hi, 27.) But this condition is not 

 retained. The proximal portion (x) separates more completely from 

 the distal and expands into a ring. The distal portion (x) on the 

 other hand swells and comes to stain more diffusely. (Fig. Hi, 28.) 

 In its later development it grows more compact, but its substance 

 seems to retain a considerable degree of plasticity, for it presents 

 much variety of shape. At times it appears to be partially with- 

 drawn into the tube. (Figs. Hi, 30 a-d.) The rest of the capsule 

 is at first quite colorless, but as it develops, longitudinal striations 

 are formed which persist for some time. (Figs. Hi, 29-31.) Fig. 

 31 shows these striations as two broad, deeply staining bands. In 

 preparations of the stage represented by Fig. 30 which have been 

 considerably destained the striations near the surface of the capsule 

 disappear, but in cross-sections four sharply staining dots indicate 

 striations of the inner tube. (Figs. 30, e-f.) 



The nucleus up to this point has remained nearly colorless, but 

 it now becomes much condensed and stains vividly with saffranin, 

 while the middle-piece takes malachite green. The capsule has be- 

 come short and broad, striations have quite disappeared and the ring 

 and plug, products of the body (x) no longer stain intensely. (PI. 3, 

 Hi, 32-34.) 



A few stages in the development of the spermatid of Homarus 

 were obtained, the material having been preserved and stained in 

 the same manner as the material from Hippa. Figs. Ho, 8, 10 

 show two stages in the formation of the inner tube. In Fig. 8 there 

 is as yet no wall formed marking oft" an inner tube within the cap- 



