440 EDWARD E. WILDMAN 
Bouin (’98) observed the ‘paranuclear bodies’ in the oocytes 
of Echinoderms breaking up into ‘corpuscles; these ‘disappeared’ 
at the moment of yolk-formation through loss of their stainabil- 
ity, but the cell seemed to be full of yolk granules and vesicles. 
Loyez (09) found in the young oocytes of certain tunicates 
the ‘nucleoles’ grouped around the nucleus. Later they form 
angular filaments, which then break up into granules. These 
increase in size, and show a clear, inner portion which does not 
stain blue in Benda’s stain, while the surface does. These vesicles 
increase in size, the unstained central portion growing at the ex- 
pense of the blue-staining surface material, until none of it is 
left. Van der Stricht (’05) finds the ‘pseudochromosomes’ in 
the oocyte of the white rat and the bat breaking up into mito- 
chondria, which then transform into yolk. Lams and Doorme 
(07) confirm these observations on the oocytes of the rat and 
the guinea-pig. 
Mitochondria in the spermatogenesis of Ascaris megalocephala 
Many other cases of this kind might be cited, but these are 
clear. In view of them my observations of the origin and devel- 
opment of the refractive body in Ascaris lead clearly to the con- 
clusion that this form and probably all of the nematodes belong 
to this fourth ‘type’ of Faure-Fremiet, for the blue-staining 
material in Ascaris spermatogenesis is certainly a yolk-forming 
material, and eventually completely transforms into yolk. Its 
place of origin is also clear. This ‘ergastoplasm’ of Prennant 
and Bouin, or ‘mitochondria’ of Meves and Korff undoubtedly 
has its counterpart in the blue-staining material in the sperma- 
tocyte of Ascaris. The authors just named thought that ‘mit- | 
ochondria’ were expelled from the nucleus of the myriapod sperma- 
tocyte into the cytoplasm. As we have seen, this is the origin 
of the blue staining material in the Ascaris spermatocyte. Here 
it forms the refringent granule, then the surface of the refrin- 
gent vesicle and later of the refractive body. It is evident that 
the term ‘mitochondria’ is ambiguous, for as we have just seen, 
it is used to stand for cytoplasmic inclusions which form yolk and 
