oe BOTANICAL GAZETTE [way 
appears that he used the very low temperature of 16°7C. He finds that some 
seeds germinate much better in darkness than in light, for example, Leucojum 
vernum, Asphodelus, Anthericus ramosus, Paris Smilacina, Polygonatum, and 
Veratrum. Phacelia and Nemophila insignis germinate very slowly and sparingly 
in white light, more rapidly and abundantly in darkness, and very quickly and 
completely in blue light. Krvyzet finds the favorable action of the light is not 
due to the actinic rays, for in many cases the rays exerting least actinic power 
are most effective in bringing about germination.—WILLIAM CROCKER. 
Heterotypic mitosis in Lilium.—In a paper on the prophase of the heterotypic 
mitosis in the embryo sac mother cell, Morrrerss describes the effect of fixing 
fluids and traces the early development of the heterotypic spirem in the megaspore 
mother cell of Lilium Martagon and L. candidum. The following conclusions are 
reached: (1) Previous to synapsis a single nuclear thread is developed, which 
in many cases can be demonstrated clearly as a definite spirem with somewhat 
regular and uniform chromatin granules. (2) There is no union side by side of 
two distinct chromatin spirems before or during synapsis, which is regarded as a 
normal process, but the greater compactness of the balled-up mass may be due 
partly to the reagent. (3) The hollow spirem following synapsis is double, due 
to the longitudinal fission, which as a rule becomes completely obscured before the 
transverse segmentation. (4) The first mitosis, therefore, separates transversely 
the two members of the bivalent chromosome. (5) The heterotypic mitosis is 
thus a reduction division, and if one chromosome differs from another potentially 
or otherwise, it is also qualitative. (6) In the presynaptic phase, that the chromatin 
may appear as large clumps instead of smaller and uniform granules has been 
suggested as being due in part to the fixing fluids, the finer and more uniform 
granules being nearer the normal. The wide divergence of the halves of the 
chromatin thread appearing occasionally in the stage of the hollow spirem may 
also be due in part to the reagent—SHicto YAMANOUCHI. 
Germination of zygotes of Spirogyra,—The germination of zygotes of Spiro- 
gyra jugalis Ktzg. has been studied by KarsTEN.3+ The germinating stage of 
the zygotes’ was obtained during November and December, and some of the 
cytological results are as follows: Two nuclei in the zygote are in close contact, 
the membranes between them staining faintly and evidently becoming dissolved. 
In the fusion nucleus two nucleoli derived from two gamete nuclei are seen for a 
time, but they finally fuse. The interior of the fusion nucleolus is vacuolized, but 
the outer portion remains and stains deeply. At the first division of the nucleus 
the synaptic stage is represented by a peculiar and irregular massing of the nucleo- 
lar membrane apne ent a peculiar elongated condition of the nucleolus, which is now 
33 MortieR, Davip M., On the prophases of the heterotypic mitosis in the embryo 
sac mother cell of Lilium. yp ae of Botany 23:343-353- pl. 23. 19 
34 KARSTEN, a Die Entwicklung der Zygoten von Spirogyra nae Ktag. Flore 
9971-11. pl. I. 19 
