SPERMATOGENESIS OF LICE 667 



by a transparent achromatic layer. The ' acroblast ' exists 

 as such during the single spermatocyte division, and finally 

 forms the ' acrosome ' of the spermatid. 



4. The description of the mitosome given for P e d i c u 1 u s 

 corporis is substantiated by an examination of that of the 

 dog-louse. Gatenby's description of a ' spireme mitosome ' is 

 criticized. 



Imperial College of Science, South Kensington. 

 May 6, 1922. 



Literature. 



1. Bowen, R. H. — "Studies on Insect Spermatogenesis, I ", ' Biol. Bull.', 



39, 1920. 

 2. "Studies on Insect Spermatogenesis, III'", ibid., 42, 1922. 



3. Doncaster, L., and Cannon, H. G. — " On the s))ermatogenesis of the 



Louse, Pediculus corporis and P. capitis ", ' Quart. Journ. Micr. 

 Sci.', 64, 1920. 



4. Foot, K. — ■" Preliminary Note on the spermatogenesis of Pediculus 



vestimenti", ' Biol. Bull.', 37, 1919. 



5. Gatenby, J. B. — " Cytoplasmic Inclusions in Germ Cells, I ", ' Quart. 



Journ. Micr. Sci.', 62, 1917. 



6. — - — " The degenerate (Apyrene) sperm formation of Moths ", ibid. 



7. — — " Cytoplasmic Inclusions in Germ Cells, V ", ibid.. 63, 1919. 



8. Gatenby, J. B., and Woodger, J. H. — " Cytoplasmic Inclusions in Germ 



Cells, IX ", ibid., 65, 1921. 



