72 THE EMBRYOLOGY OF THE HONEY' BEE 



table since it is a recognized fact that much of this want of agree- 

 ment rests on differences of interpretation. These various obser- 

 vations and interpretations have been frequently discussed, often 

 at great length, in the various textbooks and the papers which 

 have dealt with this phase of insect embryology, so that a pro- 

 longed review of the individual papers appears superfluous, but 

 in order to gain an insight into this perplexing subject another 

 means has suggested itself, which is embodied in the following 

 classified list or table of the different investigators who have dealt 

 with the origin of the mesenteron. It shows (i) the particular 

 view adopted, (2) its adherents in order of the dates of publica- 

 tion of their papers, (3) The genus or genera of insects on 

 which the observations were made. It is realized that such a 

 table fails in many instances to represent the differences as re- 

 gards details, but on the other hand these could not be brought 

 out except in a prolonged discussion, and in any event should 

 be sought in the original paper. It is also realized that this 

 table may not be altogether wanting in inaccuracies and omis- 

 sions, but a conscientious effort has been made to reduce these 

 to a minimum by consulting the original papers wherever pos- 

 sible. If this table does nothing more it will serve at least to 

 throw into relief the opposing views and interpretations, and 

 also to illustrate their diversity. 



(I) Mesenteron derived from yolk cells. 



Dohrn (1866, 1876). 



Biitschli (1870) Apis. 



Mayer (1876). 



Bobretzsky (1878) Pontia (Pieris). 



Graber (1878). 



Balfour (1880). 



Hertwig (1881). 



Weismann (1882) Rhodites. 



Tichomiroff (1882) Bonibyx. 



Ayers (1884) Oecanthus, Telias. 



Patten (1884) Neophalax. 



Korotneff (1885) Gryllotalpa 



12 Korotneff believed that only the embryonic mesenteron was formed 

 by yolk cells, the functional or larval mesenteron owing its origin to 

 blood cells. 



