1911] CURRENT LITERATURE 165 
MopiLewskr® has also described a 16-nucleate embryo sac in Gunnera 
chilensis, in which case the four megaspores, not separated by walls, all take 
part in forming the embryo sac. Although no definite proof was obtained, 
he believed the embryos to be parthenogenetic 
An interesting embryo sac is described by DESSIATOFF, 7 who finds 16 nuclei 
in Euphorbia virgata at the fertilization period. The 16 nuclei come from one ° 
megaspore, and consequently the situation is somewhat different from that 
found in Peperomia, where 4 megaspores enter into the formation of the sac. 
The 16 nuclei are arranged in four groups of four each, and one nucleus from 
each group moves to the center of the sac, where the four fuse to form the 
endosperm nucleus. There are three antipodals, and an egg apparatus of two 
synergids, and an egg. The,two other groups remain at the side of the sac 
and resemble the egg apparatus. In general, this embryo sac resembles that 
of the Penaeaceae as described by Miss StEPHENS.—CHARLES J. CHAMBERLAIN. 
e sperm nuclei of Lilium.—Since zoological literature furnishes no 
instance of the fertilization of the egg by a naked male nucleus unaccom- 
panied by any cytoplasm, and since the male nucleus in plants has in nearly 
all cases been shown to be accompanied by cytoplasm, definite proof of fertiliza- 
tion by a naked nucleus is worth recording, especially since the nucleus is 
regarded by many as the sole bearer of hereditary qualities. Both Srras- 
BURGER and KoOERNICKE have claimed that in Lilium the sperm nucleus, at 
the time of fertilization, is not accompanied by any cytoplasm. A paper by 
NAWASCHIN,® the discoverer of double fertilization, gives a very complete 
account of the generative cell and development of the sperm nuclei in the 
classic Lilium Martagon. The excellent technic, remarkably close series of 
scription and conclusions. The cytoplasm of the generative cell has a finely 
granular structure up to the anaphase of the division of its nucleus, at which 
time its cytoplasm begins to mingle with the general cytoplasm of the pollen 
tube. The mitosis which gives rise to the two male nuclei is characterized 
at every stage by sharply differentiated chromosomes, so that the sperm 
nuclei do not reach the resting stage, but remain in the condition character- 
istic of telophase. Consequently, it is not improbable that the mature nuclei 
are capable of movement. The achromatic spindle is scanty and in some cases 
doubtful, and in others cannot be identified at all, so that it is probable that 
%6 MopILEwskI, J., Zur Embryobildung von Gunnera chilensis. Ber. Deutsch. 
Bot. Gesell. 26a: 550-556. pl. 11. 1908. 
7 Desstatorr, N., Zur Entwickelung des Embryosackes von Euphorbia virgata. 
Ber. Deutsch. Bot. Gesell. 29:33-39. figs. I7- 1911. 
*8 NAWASCHIN, SERGIUS, Niheres iiber die Bildung der Spermakerne bei Lilium 
Martagon. Ann. Jard. Bot. Buitenzorg. II. Supplement IIT. 871-904. pls. 33, 34. 
IQIo, 
