HARRIS : DIMORPHISM OF CAMBARUS. 55 



material is, I believe, in as good condition as that upon which many 

 of our cytological papers are based. 



No. 1. C. immunis. F. I. About two inches long. August 24, 

 1900. 



One lobe eectioned. At the proximal end are a few emptied follicles and more 

 with mature spermatozoa. Also various stages of spermatid transformation, 

 the earlier stages being for the most part towards the distal end. The sperma- 

 tids extend somewhat more than one-half the length of the lobe. Then follow 

 spermatocytes; and finally an area of spermatogonia, about one-sixth the length 

 of the lobe in width. An occasional division figure is seen among these sperma- 

 togonia. 



No. 2. C. immu7iis. F. I. About two inches long. July 27, 1900. 

 Sections not in plane to show regions to best advantage, but condition seems 

 to be about same as No. 1. 



No. 3. C. immunis. F. II. About two and one-half inches long. 

 August 2, 1900. 



All lobes sectioned. Sections of anterior lobes not perfect. One of anterior 

 lobes eeeme to have an unusually large number of spermatogonia. Condition 

 otherwise seems to be about same as No. 1. 



No. 4. C. immunis. F. II. Size of individual not recorded; 

 probably about two inches long. Still slightly soft from exuviation. 



Only one lobe sectioned. With the exception of a little different appearance 

 of the spermatogonia, which, from comparison with other material, seems to me 

 to be unimportant in this connection, this seems to agree exactly with No. 1. 



No. 5. C. irnmunis. F. I. About two inches long. August 24, 

 1900. 



One lobe sectioned. Proximal end shows follicles with mature spermatozoa. 

 Farther back are seen follicles containing various stages of spermatid transforma- 

 tion; then follow spermatocytes and finally spermatogonia. Condition practi- 

 cally same as No. 1. Vas deferens contains a considerable number of spermatozoa. 



No. 6. C. immunis. F. I. About two inches long. August 24, 

 1900. 



Only one lobe sectioned. In about same condition as No. 1. 



No. 7. C. immunis. F. I. About two and one-half inches long. 

 August 31, 1900. 



One lobe sectioned. Conditions about the same as No. 1. A section through 

 the vas deferens shows the presence of a considerable number of spermatozoa. 



No. 8. C. immunis. F. II. About three to three and one-half 

 inches long. August 24, 1900. 



One lobe sectioned. Condition practically identical with No. 1. 



No. 9. C. immunis. F. II. About two and one-half inches long. 

 August 31, 1900. 



One lobe sectioned. Condition almost exactly same as that of No. 1. 



