A critical study of the cytology of Crepis virens. 
101 
diiring rest; and \ve may say without reserve that their presence at all 
stages of rest between the successive premeiotic divisions seems to con- 
cliisively prove the permanence of the chromosomes froni one cell genera- 
tion to another” (p. 558). 
Malte (30) has shown that the enth-e chromatic substance of the 
resting nuclei in the Euphorbiaceae is concentrated into isolated “Chroma- 
tinkörner”. In the resting vegetative nuclei of Mercurialis annua the 
Körner not only agree in number, but also in size and in shape with the 
chromosomes. This fact convinces him “daß sie in der Tat Chromosomen 
darstellen, die im Ruhezustand des Zellkerns ihre Individualität bei- 
behalten” (p. 87). 
Kichols (38) working on the development of the pollen of Sarracenia 
conld neither establish any constancy in the number of points round 
which the chromatm collected, nor that they were coincident with the 
number of the chromosomes. 
Lewis (27) describes the chromatic conteuts of the resting nuclei 
of Pinus and Tlinja as somewhat large granulär lumps, connected liy 
dehcate anastomosing linin Strands. The number of the lumps is greatly 
in excess of that of the somatic number of chromosomes. 
Schaffner (49) has shown in the young microsporocyte nuclei of 
Agave virginica that chromatic masses appear which approxiniate to the 
reduced number of chromosomes. As the prophase advances they become 
increasingly conspicuous. Schaffner believes that these masses are 
the ‘pro chromosomes’ of Overton, and that they represent pairs of 
individual chromosomes which are orientating theniselves preparatory 
to sph’eme formation. 
Lundegardh (29) examined Calendula officinalis, Achülea mille- 
folium and Trollius eurofaeus. He found that ‘gamosomes’ are definitely 
paired in Calendula and in AchiUea, whereas in Trollius some of the 
chromatic aggregations are paired and some are single. Düring pro- 
phase these collect into ‘Chromatinklumpen’ whose number is consid- 
erably in excess of that of the somatic chromosomes. Lundegardh 
suggests that in the case of Trollius these should be caUed ‘Prochromo- 
somenteile’ instead of ‘prochromosomes’. 
Gates (16) has described chromatin bodies m the nuclei of the mer- 
istematic ceUs of Oenothera ruhrinervis which lie appressed against the 
nuclear membrane. In the presynaptic phases similar deeply staining 
bodies accuniulate near the periphery of the nucleus and are swept by 
the reticulum into synapsis. These bodies exhibit no constancy in their 
number, size, or shape. 
