Nachdruck verboten. 



Ueber Setzung sr eckt vorbehalten. 



On Nucleolar Structures of the hypodermal Cells of the 

 Larva of Carpocapsa. 



By 

 Thomas H. Montgomery jr., Philadelphia. 



With Plate 27. 



As has been shown by the author ^) three main kinds of so-called 

 "nucleolar" structures may be distinguished: the true nucleoli 

 (plasmosomes) which do not react chemically like the chromatin ; 

 karyosomes, which are merely thickened nodal points of the chro- 

 matin reticulum in the resting nucleus; and bodies termed by me 

 "chromatin nucleoli", which show the staining reactions of 

 chromatin, but which are not integral parts of the chromatin reti- 

 culum. The chromatin nucleolus of the spermatocyte of the first order 

 of the Hemipteron Tentatoma (Euchistiis) was shown by me to be a 

 metamorphosed chromosome ■^). 



The present contribution concerns the mode of formation of 

 chromatin nucleoli in resting hypodermal nuclei of Carpocapsa pomu- 

 nella Linn., a Lepidopterous insect. A large larva of this species 

 fixed in Carnoy's fluid (glacial acetic, 1 part, absolute alcohol, 6 parts, 

 chloroform, 3 parts) was the basis of the study. A strongly pene- 

 trative fixative is necessary , on account of the thick hypodermal 

 cuticle. 



1) Comparative c3'tological studies with especial reference to the 

 morphology of the nucleolus, in: Journ. MorphoL, V. 15, 1899. Ob- 

 servations on various nucleolar structures of the cell, in : Biol. Lectures 

 for 1898, Woods Holl Laboratory. 



2) The spermatogenesis in Pentatoma up to the formation of the 

 spermatid, in: ZooL Jahrb., V. 12, Anat., 1898. 



