1915] CURRENT LITERATURE K 163 
in its present form, and it is to be hoped that immediate and radical revision 
may make of it an acceptable and trustworthy guide to the literature of this 
interesting field——JosEpH S. CALDWELL. 
NOTES FOR SIQVDENTS 
Experimental embryology.—Morphologists and experimental workers have 
s n 
by morphology and cytology. It is‘becoming increasingly evident that results 
can be more properly interpreted in the additional-light afforded by supple- 
mentary researches in a related field. The value of this cooperative method 
is emphasized in a recent paper by KusANo! on angiosperm embryology. A 
favorable form for such study was found in the orchid Gastrodia elata. Since 
the inflorescence develops at the expense of material stored in a tuber, it is a 
simple matter to maintain the plant under normal nutritive conditions. Some 
of the results of KusAno’s research, which is still in progress, are cited below. 
e normal development in Gastrodia is as follows: A subepidermal 
archesporial cell becomes the megaspore mother cell and undergoes the two 
are sometimes haploid and sometimes diploid. The embryo sac contains only 
4 nuclei, 3 of which are organized as an egg apparatus. This reduced condition 
is regarded as an economical specialization correlated with the peculiar vege- 
tative habit. Many irregularities which occur are related to poor nutrition. 
At fertilization, which occurs only in haploid sacs, one of the male nuclei 
fuses with the egg nucleus, while the other fuses with the single polar and 
a synergid nucleus. The fertilized egg forms the usual undifferentiated 
proembryo, which is nourished through the suspensor and large nucellar 
cells. The endosperm nucleus does not divide. The following time schedule 
was determined: two days before the flower opens the ovule is yet in a rudimen- 
tary stage; the embryo sac is completed 3 days after bloom; fertilization occurs 
the 4th day after pollination; the fertilized egg divides the 5th day; the seed 
is completed the 14th or 15th day; the capsule dehisces about the 23d day. 
This exceptionally rapid development (for Orchidaceae) is correlated with the 
fact that it occurs at the expense of stored food. Occasionally two arche- 
sporial cells arise in a single ovule and undergo complete development. 
An extended series of experiments led to the following conclusions: After 
a few days the fertilizing power of the pollen is lost and the ovules become 
4 Kusano, S., Experimental studies on the embryonal development in an angio- 
sperm. Jour. Coll. Agric. Tokyo 6:7-120. pls. 5~9.. figs. 28. 1915 
