94 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



and these bodies themselves have increased in size, so that instead of 

 being comparable to the central corpuscle, they are nearer the size of 

 the entire vesicle of the final stage (Plate 5, Figs. 37, 41). At this 

 stage there are two kinds of stained bodies, — those within the vacuoles 

 (cp. ia'vac.) and those included in the lamellae between the vacuoles 

 (cp. ia'll.). Safranin (Fig. 37) does not allow one to distinguish 

 between these, but the triple stain of safranin, gentian violet, and 

 orange does, giving the intra vacuolar bodies a light yellow, and the 

 intralamellar ones a deep purple color. At a slightly earlier stage 

 the intravacuolar bodies also take the purple stain, so that it may be 

 that these two structures have a common origin. The nucleus takes 

 part in none of these changes. It is occasionally seen in safranin 

 preparations (Fig. 38, nl.) , and haematoxylin shows it to be practically 

 unchanged, and universally present at considerably later periods (Plate 

 5, Fig. 44). 



The next and most important stage is that in which some of the 

 intravacuolar bodies have acquired a central more deeply stained 

 corpuscle. Their size is about the same as before, but they stain 

 more faintly (Fig. 38). In the next stage (Plate 5, Figs. 39, 40) all 

 of these bodies have developed a central corpuscle; they now take a 

 still fainter stain, and have approximated still more closely in size to 

 the vesicles of the final stage. In fact they resemble the latter so 

 closely that most of the transitional stages from one to the other are 

 found among the test cells of a single ovum. As these bodies acquire 

 their final dimensions, they assume a peripheral position, crowding the 

 remains of the intravacuolar cytoplasm towards the centre, in which 

 are contained the deeply stained intralamellar bodies that treatment 

 with safranin makes so prominent (Plate 5, Figs. 42, 43). 



The nucleus, which from the start of the process has a peripheral 

 position, persists almost unchanged until the vesicles have become 

 thoroughly established (Fig. 44). It is still oval, but stains more 

 faintly than before. Later still, while the vesicles remain entirely 

 unchanged, the nucleus slowly degenerates, becoming at first paler, 

 and distorted by the pressure of the vesicles (Fig. 45), and then refus- 

 ing to take the stain altogether, but persisting as an irregular periph- 

 eral refractive patch (Fig. 42, nl.) , which finally seems to vanish 

 entirely (Fig. 46). 



This process, like that in the follicle cells, has no prospective mean- 

 ing, for the test cells take no part in the development of the embryo. 

 In life they have a decided yellow color in this species, while the 



