54 KANSAS UNIVERSITY QUARTERLY. 



of the sexual organs, to get some idea of the relation of the repro- 

 ductive elements to the physical condition of the animal, and in this 

 way come a little nearer to the determination of the true significance 

 of the occurrence of the two forms. 



As the title indicates, I do not intend this as a final paper, there be- 

 ing many important points yet to be ascertained before this interest- 

 ing problem is fully solved. I feel, however, that, in addition to the 

 general survey of the subject, the question, the answer to which was 

 the original subject of the investigation, has been definitely and con- 

 clusively answered, and that the results obtained are of sufficient in- 

 terest to warrant their appearance here, even before other points 

 which have been suggested in the course of the work are decided. 



My material was fixed in Flemming's fluid, sometimes with a vary- 

 ing amount of acetic acid, in hope of counteracting the tendency to a 

 vacuolation of the cytoplasm during the process of division, embedded 

 in parafiin, and sections prepared by the usual cytological methods. 

 Heidenhein's iron-htematoxylin and the safranin-gentian-violet- 

 orange-G methods were used principally as staining reagents. 



I wish to express here my gratitude to Prof. C. E. McClung and 

 Mr. W. S. Sutton, of the department of zoology, University of Kansas, 

 where the work was done, for useful suggestions. 



It will be observed that in comparing the condition of the testes 

 of different individuals, I have frequently used some qualifying term ; 



as, for example, "Condition about the same as No. ." This 



course seemed necessary to strict accuracy ; for while, so far as the 

 essential parts are concerned, they may be alike, it must be borne in 

 mind that considerable individual variation is to be expected. Vari- 

 ous causes affect the relative development of the germ-cells in differ- 

 ent individuals. In Camharus, the greatest variation occurs in the 

 general form of the testis — a condition which would imply consider- 

 able variation in the relative shape and arrangement of the different 

 germ-cell zones. The normal testis is three-lobed — two anterior and 

 one posterior ; yet those which have become almost completely four- 

 lobed through the division of one of those already existing are not at 

 all uncommon. 



The following table shows the condition of the testes of a number 

 of individuals of the two forms. Usually but one lobe was examined ; 

 however, in cases where more than one lobe was sectioned, the con- 

 dition was usually found to be essentially the same. It will be noted 

 that some of the material is not in the best condition, having been 

 prepared under unfavorable circumstances. I might say, however, 

 that in no case have conclusions been even suggested from poor sec- 

 tions which seemed in any important way different from other 

 preparations with which they were compared. The greater part of my 



