1 1 2 MUNSON. [Vol. XV. 



Introduction. 



This work on the history and morphology of the ovarian egg 

 of the King Crab — Limulns polyphenms — has been done in the 

 Zoological Laboratory of the University of Chicago, and in the 

 Marine Biological Laboratory at Woods Holl, Mass., under 

 the direction of Professor Whitman. 



The object of the work has been to determine, so far as 

 possible, the organization of the egg during its different stages 

 of growth, and to give a connected history of its phases. The 

 vitelline-body and centrosome have received special attention. 



Much of the more valuable literature on this subject is of so 

 recent date that it has not seemed advisable to encumber the 

 paper with a historical compilation. Papers of special interest 

 will be referred to in connection with my own observations. 



Historical. — The main facts concerning the position and 

 external form of the ovary have been known since 1828, when 

 Strauss Durckheim made known the internal anatomy of Limulus. 



Somewhat later, 1838, J. Van Der Hoeven also published an 

 account of the ovary, its mode of branching, its ramifications 

 throughout the cephalothorax, and the astonishing number of 

 eggs produced. 



Lockwood ('70) has treated in a popular, but exceedingly 

 interesting way the habits of Limulus, and mentions many 

 interesting facts in regard to its development. 



Packard ('71) noted some points in the development of the 

 ovary, and among other things called attention to the laminated 

 structure of the egg membrane, which he calls a chorion. 



Owen ('73) described and figured the ovary of Limulus, and 

 showed the relation of the ovarian tubes to the terminal ovi- 

 ducts, as well as the relation of the right and left ovary to each 

 other and to the underlying parts. 



Among those who have devoted attention more directly to 

 the nature of the ovarian eggs may be mentioned Ludwig, 

 Gegenbaur, and Kingsley. 



Ludwig ('74) called attention to the character of the germi- 

 nal epithelium, and especially to the cell nature of the egg. 

 He, however, based all of his conclusions on the observations 



