Vol. XXXII. January, 1917. No. i. 



BIOLOGICAL BULLETIN 



CYTOPLASMIC STRUCTURES IN THE MALE GERM 

 CELLS OF RHOMALEUM MICROPTERUM BEAUV. 



HAROLD H. PLOUGH, 

 ZOOLOGICAL LABORATORY, COLUMBIA UNIVERSITY. 



In a recent paper Lewis and Robertson gave an account of 

 certain cytoplasmic structures in the male germ cells of Chor- 

 thippus curtipennis Scud, as seen by the tissue culture method. 

 It is the purpose of this paper to give somewhat similar data 

 for the Florida lubber grasshopper, Rhomaleum micropterum 

 Beauv., on the basis of both fixed and living material. My 

 observations were made mainly in order to determine the origin 

 and significance of the chromatoid body. They closely parallel 

 those of the previous authors, and may perhaps clear up some 

 doubtful points. 



While studying the maturation phenomena in Rhomaleum in 

 1914 it was found that a small round densely staining body was 

 always present in the cytoplasm of the cells of the late growth 

 period. Further study disclosed the fact that this body appeared 

 in the very early growth period, enlarged up to the stage of dia- 

 kinesis, and at both the first and second maturation divisions 

 passed unchanged into one of the two daughter cells. During the 

 metamorphosis of the spermatid this body passed gradually 

 down into the tail region of the future spermatozoon, and was 

 eventually cast off and degenerated in the lower end of the follicles. 

 This history is exactly parallel to that of a similar but larger 

 body described by Dr. E. B. Wilson ('13) in the spermatogenesis 

 of the hemipter Pentatoma senilis, and called by him the "chroma- 

 toid body." It is now known that a granule or granules of 

 similar behavior are present in the developing male germ cells 

 of the following forms: horse, pig, bull, rabbit, crayfish and 



