May, 1906.] 
A Redudug Division in Ascaris. 
525 
Literature Cited. 
With two exceptions, I have listed only the papers directly 
referred to in the text. The exceptions are -Guyer’s extremely 
important work published before the rennaissace of Mendel’s 
Law, which have not received from writers on kindred subjects, 
the attention they deserve. 
1. Berghs, Jules. La Formation des Chromosomes Hetero- 
typiques dans la Sporogenese Vegetale. II Depuis la 
Sporogonie jusqu’an Spireme Definitiv. La Cellule 21 : 
38.3-397 PI. 1. 1904. 
2. Brauer, a. Zur Kenntniss der Spermatogenese von 
Ascaris megalocephala. Archiv f Mik. Anat. u. Entw. 
42 : 168. 1893. 
3. Gregoire, Victor. Les Resultats Acquis sur les Cineses de 
Maturation. Premiere Memoire; Revue Critique de la 
Literature. La Cellule 22 ; 221—376. 190.5. 
Material cited at p. 330. 
4. Guyer, M. F. Spermatogenesis of Normal and Hybrid 
Pigeons. Chicago, 1900. 
5. . Hybridism and the Germ-Cell. Univ. Cincin- 
nati. Bull. 21. 1902. 
6. Montgomery, Thos. H. Some Observations and Consider- 
ations on the Maturation Phenomena of Germ Cells. Biol. 
Bull. 6 : 137. 1903. 
7. Moszkowski, Max. Zur Richtungskorperbildung von As- 
caris megalocephala. Archiv f. Mik. Anat. u. Entw. 59 : 
388. 4 fig. 1902. 
8. Tretjakof, D. Die Bildung der Richtungskorperchen in 
den Eieren von Ascaris megalocephala. Archiv. f. Mik. 
Anat. u. Entw. 65 : 358-583. PI 21. Die Spermatogen- 
ese bei Ascaris megalocephala. p. 383-435. PI. 22, 23. 
fig. 1. 1905. 
Explanation of Plate XXXIII. 
The figures were drawn with a Leitz 1-16 oil immertion ob- 
jective and a Bausch and Lomb 1-2 in. ocualr. They were drawn 
with the aid of a camera lucida and are reproduced 2-3 their 
original size. 
Fig. 1. A nucleus just passing from the resting stage. The nuclear 
membrane is extremely faint, being on the verge of disappearance. 
Fig. 2. The chromatin network well broken up and on the way to 
the fcrmation of the continuous spirem. 
Fig. .3. A continuous spirem. This is wrapped so tightly that it is 
not possible to be certain all the strands run exactly as drawn. The nuc- 
leus was, however, in this stage and about as drawn. 
Fig. 4. Slightly later than the last, showing the first appearance of 
doubled granules on the still single linin spirem. As in hg. 3, the spirem 
is too complicated to be followed with certainty but it in the main as 
represented. 
