THE EMBRYOLOGY OF A SCORPION. Ill 



spheres, which contain one, two, or more of them. In the 

 larger spheres they are much more numerous and much 

 smaller. Many of the spheres show round holes as if the 

 darkly staining bodies had dropped out. It may be, however, 

 that these cavities contained a fatty or oily substance, which 

 has been dissolved out in the course of embedding and 

 mounting. 



The only structures remaining to be described in connection 

 with the ovary are the corpora lutea mentioned above (fig. 7). 

 These are irregularly shaped bodies of about "12 mm. in 

 diameter, showing a slight tendency to radiate structure, and 

 containing a considerable number of nuclei, which are scattered 

 about without any definite arrangement. They project from 

 the surface of the ovarian tubes, and are evidently the collapsed 

 remains of the follicles after the egg has passed out. I was 

 confirmed in my idea that these were corpora lutea by their 

 resemblance to the structures described by v. Sieboldi in the 

 ovary of Apus. They differ from these latter, however, in not 

 containing fluid. 



First Period. — Formation of Blastoderm. 



The egg is fertilized in the follicle, from which it does not 

 begin to pass out until the end of this period. It then passes 

 into the ovarian tube in which it undergoes the rest of its 

 development, the young when born being exactly like the 

 parent in form. Kowalevsky and Schulgin" state that the egg 

 in Androctonus is not fertilized until it has entirely left the 

 follicle, and passed into the ovarian, tube, or, as he calls it, 

 uterus. I can hardly believe this to be the case, but it is quite 

 possible that it leaves the follicle at an earlier stage in 

 Androctonus than in Euscorpius. 



Stage A. — I have not, unfortunately, been able to observe 

 the processes of fertilization and the formation of the first 

 segmentation-spheres. I should think it probable that the 



1 V. Siebold, 'Beitrage zur Parthenogenesis der Arthropodeu,' Leipzig, 

 1871, p. 191. 



" Loc. cit., p. 526. 



