A further Account of the Spermatogenesis 



of Lice. 



By 



H. Graham Cannon. 



With 1 Text-figure, 



In 1919 the late Professor Doncaster and the present author 

 investigated the gametogenesis of the hce Pedi cuius 

 corporis and Pedi cuius capitis. An account of this 

 work was published during the following year (3). The cytology 

 of the spermatogenesis was found to be so peculiar and in some 

 respects unique, that it was decided to extend the work to 

 other lice. At the time of his death Professor Doncaster was 

 working on the gametogenesis of the horse-louse and the dog- 

 louse. The material collected by him together with his notes 

 was handed over to me by Professor J. Stanley Gardiner. 



A perusal of the notes showed that Doncaster had only 

 cursorily examined his material and had not arrived at any 

 new conclusions. For this reason it was not considered advis- 

 able to publish any further account based on the new material. 

 However, at the end of 1919 an account of the spermatogenesis 

 of Pediculus vestimenti was published by Miss Foot (4) 

 which differed so considerably from that published by Doncaster 

 and myself that a thorough examination of Doncaster's new 

 material seemed called for, and the present note is an account 

 of that work. 



The material examined consisted of testes of the dog- 

 louse (Lignognathus pi lifer us) and of the horse-louse 

 (Haematopinus asini). Some fixed material of the last- 

 named species, obtained from a donkey, was kindly sent to me 

 recently by Mrs. Bisbee of Liverpool University, who was 

 assisting Professor Doncaster in this work. I also obtained 



