GERM CELLS OF ARGAS 653 



extra-nuclear bodies correspond in color to the plasmosome and 

 do not stain like the chromatin, and with Bensley's acid-fuchsin- 

 methyl-green (or other counter stain) they and the nucleolus 

 take the brilliant red of the acid dye. One is led to the conclu- 

 sion that these extra-nuclear bodies represent products of nuclear 

 activity similar to those substances found in the plasmosome 

 and that they are of little further significance in the economy 

 of the cell, being thrown out into the cytoplasm where they are 

 later dissolved and absorbed after the manner in which the plas- 

 mosome itself disintegrates at the time of maturation. 



Vesicular bodies and oil drops 



As has been noted, the vesicular bodies are first seen during 

 the early growth stages, having the form of elongated, fusiform 

 fibers which appear among the mitochondria, both where these 

 granules are thickly aggregated and where less concentrated. 

 There is no evidence that the fibers arise directly from mito- 

 chondria as described by Sokolow ('13) for structures of some- 

 what similar form in the spermatocytes of the scorpion, but they 

 appear to arise de novo in the cytoplasm. There is some evi- 

 dence that the fibers may multiply by transverse fission, although 

 this is doubtful. The metamorphosis of a fiber into a vesicle 

 is accomplished by the thickening of the fiber in the middle, 

 followed by the appearance of a cavity in the thickened portion, 

 which gradually increases in extent until a distinct vesicle is 

 formed (figs. 5, 6 and 7). When the stage represented by figure 

 8 is reached, all of the fibers have been transformed into vesicles 

 and some of the vesicles are cylindrical in shape with thin- 

 walled ends. Apparently these bodies increase in number during 

 the remaining period of growth but no evidence can be pre- 

 sented as to the exact method of multiplication. 



Following maturation, the vesicular bodies take part in the 

 polarization of the spermatids by separating from the true 

 mitochondria and moving toward the nucleus. Figures 12 to 

 15 illustrate these rearrangements and they also show the begin- 

 nings of certain degenerative processes which lead to the disinte- 



JODRNAL OF MORPHOLOGY, VOL. 28, NO. 2 



