DEVELOPMENT OF PLATYPHVLAX. 55 



made up in its turn as in a nucleus — a quite incorrect view, of 

 course, as we know it. In his Fig. 132, A and B, he indicates 

 the difference in form of the nuclei from young and old larvae of 

 a microlepidopter. 



Gilson (1890) figures sections of spinning-gland nuclei of lepi- 

 doptera, but does not distinguish the character of the nuclear 

 contents, nor does he discuss the nature of the material. The 

 same author (1894) distinguishes the two materials in glands of 

 trichoptera. He mentions the parts as follows : " Disons seule- 

 ment qu'il existe au sein de I'amas de trongons nucleiniens, des 

 corps arrondis, chromatique, des nucleoles particuliers qui souvent 

 laissent voir dans leurs interieure des cordons nucleiniens, sem- 

 blables a ceux qui constituent la grande masse du contenu 

 nucleaire." 



Korschelt (1896), working on various species of lepidoptera, 

 used a modification of the Ehrlich-Biondi stain. He found the 

 larger particles (macrosomes) to stain green, the smaller ones 

 (microsomes) to stain red, and concluded that the macrosomes 

 must be regarded as chromatin, the microsomes as nucleoli. 



Meves (1897), employing various methods of staining, shows 

 that the microsomes of Korschelt are chromatin granules, and 

 that the macrosomes of that author must be regarded as nucleoli. 

 He employed Heidenhain's formula of the Ehrlich-Biondi stain 

 and got the opposite result to that of Korschelt, who used a 

 formula with the methyl green much stronger. 



Korschelt (1897) upholds the view previously expressed by 

 him as to the nature of the macrosomes and microsomes. 



Flemming (1897) agrees with Meves. 



Henneguy (1904), p. 463, refers to the conclusions of Korschelt 

 and Meves and records his researches as agreeing with the latter. 



Marshall and Vorhies (1906) conclude as the result of the use 

 of various stains, that the larger bodies are nucleoles, the smaller 

 granules chromatin. 



It is evident from the above review that all of our evidence upon 

 the nature of the stainable materials is that derived from the 

 staining reactions. While with our present knowledge of such 

 reactions the proof thus offered is very good, yet the presence of 

 such large amounts of nucleolar material as are found in the 



