96 bulletin: museum of comparative zoology. 



5. Davis ('08), Acrididae and Locustidae. 



6. Buchner ('09), Gryllus, Oedipoda. 



7. Stevens ('10b), Forfieula. 



8. Brunelli ('09, '10), Gryllus, Tryxalis. 

 b. Second maturation division reductional. 



1. Sutton ('02, '03), Brachystola. 



2. Baumgartner ('04), Gryllus. 



3. McClung ('05, '08a, '14), various Orthoptera. 



4. Stevens ('05), Stenopalmatus. 



5. Nowlin ('08), Melanoplus. 



6. Finney ('08), Phrynotettix. 



7. Robertson ('08) Syrbula. 



8. Carothers ('13), Acrididae. 

 B. Parasynapsis assumed or described. 



a. First maturation division reductional. 



1. Gerard ('09), Stenobothrus. 



2. Morse ('09), Blattidae. 



3. Stevens ('12a), Ceuthophilus. 



4. Robertson ('15), Tettigidae. 



b. Both divisions equational. 



1. Vejdovsky ('11-12), Locustidae. 



c. Division neither reductional nor equational. 

 1. Otte -('07), Locusta. 



This classification ^ is interesting from two points of view. In the 

 first place, it indicates the diverse results that have been obtained by 

 the various investigators working on a limited group within which one 

 might reasonably expect to find a high degree of uniformity in chromo- 

 somal behavior. In the second place, the results that I have obtained 

 do not come under any of the classes in the above outline. As stated 

 on previous pages, I have shown (1) that the spermatogonial chromo- 

 somes develop into the fine leptotene threads, which conjugate by 

 paras;>aiapsis without the conjugants losing their identity, that is, the 

 line of conjugation is visible tlu-oughout the growth-period as the 

 'primary longitudinal split'; (2) that a second longitudinal split at 

 right angles to the first occurs in the early postspireme stages; and 

 (3) that the tetrads become so oriented on the first maturation spindle 

 that the resulting division is equational. Each of the dyads of the 

 second spermatocj^tes consists of parts of the two original conjugants, 



' I have omitted reference to some papers which were non-committed on the points under 

 discussion. 



