2 HAROLD H. PLOUGH. 



probably in the rat, mouse, and a number of Hempitera. It 

 seems probable therefore that the appearance and elimination 

 of such material from the spermatozoa is a fairly general phe- 

 nomenon throughout the animal kingdom. 



The recent study of Lewis and Robertson on the living germ 

 cells of Chorthippus curtipennis showed that certain granules 

 were present in the spermatogonia and passed on somewhat 

 enlarged into the metamorphosing spermatids. From the fact 

 that these 'granules stained with neutral red in contrast to the 

 mitochondria they were called "neutral red granules." Up to 

 the time their paper was published the work with Rhomaleum 

 had been carried exclusively with fixed material, but in view of 

 the similarity of behavior between these granules and the 

 chromatoid body in the Florida grasshopper it was believed 

 that they were of similar material and significance. Work on 

 the living male germ cells of Rhomaleum during the past summer 

 has confirmed this belief in every respect, and has made it 

 possible to add a few facts to the data of the previous authors. 



The material from which the observations were made was 

 secured from the Supply Department at Woods Hole during the 

 summers of 1915 and 1916. That used for permanent prepara- 

 tions was fixed in the usual fixatives including the modified 

 Flemming's fluid used for the Benda mitochondrial technique. 

 A large number of different staining methods were employed 

 including the Auerbach mixture, the Borel stain, together with 

 the Altmann acid fuchsin stain and the alizarin-crystal violet 

 combination of Benda for mitochondria. The osmic mixtures 

 were invariably the best cytoplasmic fixatives and from material 

 so treated all of the drawings from permanent preparations were 

 made. The methods used with the living material were for the 

 most part those of Lewis and Robertson. Intravitam staining 

 with janus green B and neutral red was employed, the stains 

 being used both separately and together. The culture medium 

 used was the modified Locke's solution of these authors made 

 up with sea water, though some follicles were stained in Ringer's 

 solution with fair success. The tissue cultures were only par- 

 tially successful, most of the cells being abnormal after thirty-six 

 hours. This was probably due to lack of familiarity with the 



