PRELIMINARY NOTE ON THE SPERMATOGENESIS 

 OF PEDICULUS VESTIMENTI. 1 



KATHARINE FOOT. 



In response to a request from Col. Alexander Lambert I came 

 to Paris, December, 1917, in order to study Pediculus vestimenti 

 from the point of view of the biologist in the hope of getting 

 some data that might be of service to the investigators who were 

 studying the louse as a possible transmitter of certain diseases 

 prevalent among the troops. 



In an exhaustive and masterly study of the problem in rela- 

 tion to trench fever, Col. Strong has shown that the lice can 

 unquestionably transmit this disease and has proved beyond 

 question what was heretofore merely a surmise. 



Such data as I have been able to collect that may have some 

 bearing on the problems in relation to disease have been reported 

 to the Research Department of the American Red Cross; but I 

 have omitted from such reports purely cytological data which 

 have no apparent practical value. 



As far as I know, no report has been published of any work 

 done on the chromosomes of the louse, and as P. vestimenti has 

 been classed as an Hemipterous insect I was interested to see if 

 the chromosomes have the same bizarre morphological char- 

 acteristics as are typical of so many Hemiptera. 



The spermatocyte chromosomes are very minute, so minute 

 that I have as yet found it impossible to demonstrate the method 

 of division of the second spermatocy tes ; but I have several 

 entirely satisfactory stages of the first spermatocyte chromosomes, 

 and as these have the same morphological characteristics as the 

 corresponding stages in other species of Hemiptera, it is quite 

 permissible to assume a like correspondence for the second 

 division. 



1 My grateful acknowledgments are due to the late Professor Blanchard, who 

 gave me a most cordial welcome to his laboratory at the Ecole de Medecine. He 

 not only gave me ample space for my work but the sympathy and encouragement 

 I received from him and the members of his staff made it possible for me to con. 

 tinue my investigations of these repulsive insects. 



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