80S 
Dl L. SOOS 
the spireme begins to form. The threadlike structure of the chromatin 
is more evident in the following stage (Pl. VII., Fig. 12.), which is 
characterized by the one sided contraction of the chromatin (synapsis). 
The chromatin occupies one side of the nucleus, the other part remai¬ 
ning quite clear ; the nucleolus lies amongst the chromatin threads, near 
the wall of the nucleus. 
The one-sided contraction of the chromatin is very characteristic 
for the germ-cells of many animals and plants. In animals it was 
observed in the following forms: Coelenterata : Sycandra (?, Jörgensen), 
Gonionemus (Bigelow); Worms: Ascaris (Beauer, Schabaschnikoff, 
Tretjakoff), Planaria lactea (Arnold), Dicrocoelium lanceatum (Gold¬ 
schmidt), Lumbricus (Calkins) ; Annelida (Vejdovsky, A. and K. E. Schrei¬ 
ner); Arthropoda : Copepoda (Häcker, Bückert, Berat), Ostracoda (Wol¬ 
tereck), Peripa tus (Montgomery), Insects (Henkin g, Montgomery, Paulmier, 
de SiNÉTY, Baumgartner, Farmer and Moore, Stevens, Otte, Nowlin, 
Davis, Munson, Morse), Spiders (Wallace); Mollusca (Bolles Lee, 
Bonnevie, Popoff); As deliae : dona (Maréchal); Vertebrates: Amphioxus 
(Maréchal), Fishes (Moore, A. and K. E. Schreiner, Farmer and Moore, 
Maréchal), Amphibians (McGregor, Janssens, Eisen), Mammals (Wini¬ 
warter). As is to be seen from this list, which does not pretend to be 
complete, the synapsis is a nearly general condition in germ-cells. 
With regard to the question, whether synapsis is a normal condition 
of cells, or is caused by the influence of the reagentia, opinions are 
very different. According to Sargant synapsis can be observed also in 
living material (pollen-cells). Lérat (61) and Meves (73) are of the 
opinion that synapsis is partly a normal appearance, partly artifact, 
and this is the opinion of many botanists (Strasburger and his school). 
On the contrary Vejdovsky (121) decidedly holds to a natural condition; 
according to Popoff (94) it is in the ovocytes of Paludina not an arti¬ 
fact ; according to Munson (84) the synapsis of the spermatocytes of 
Papilio rutulus is not the result of the reagentia ; according to Arnold (3a.) 
in Planaria lactea, and Morse (83a.) in Periplaneta americana is a nor¬ 
mal condition. Other investigators regard it as the result of the reagentia 
used (McClung, Janssen, Bolles Lee, Davis, etc.). Janssens (52) empha¬ 
sized the fact that he found the chromatin onesidedly contracted, only 
in the inner part of his preparations where the fixing fluid could not 
enter sufficiently, on the contrary in the outer parts he did not find 
synaptocytes. Davis (19) also refers to the fact that in the peripheral 
parts of his preparations he has not found the chromatin contracted. 
Bolles Lee (10) states the contraction of chromatin in the male germ- 
cells of Helix pomatia to be of pathologic appearance, because he 
I 
