1904] CURRENT LITERATURE 73 
evident, so that there can be no reduction division in Weissmann’s sense. 
The statement that Trillium (with Naias) has the smallest number of chromo- 
somes yet known in phanerogams reveals another oversight of American 
literature, since the numbers in Canna are 6 in sporophyte and 3 in the: 
gametophyte. Ina few cases the embryo sac of Trillium showed ten nuclei 
instead of eight, the two extra nuclei having arisen through fragmentation of 
two of the eight nuclei. 
Double fertilization occurs in both genera. In the union of the sperm 
nucleus with that of the egg, the fusion is complete, a resting nucleus being 
formed. The second sperm nucleus and also the two polar nuclei pass into 
the spirem condition before uniting, so that there can be no real fusion of 
chromatin in the formation of the endosperm nucleus. How long the 
chromatin of these three nuclei remains independent was not determined.— 
C. J. CHAMBERLAIN. 
ALL ECOLOGISTS are acquainted with Bonnier’s great contributions to 
experimental anatomy, especially in his studies of alpine plants. e has 
recently” presented a second communication dealing with his Mediterranean 
cultures, which were established near Toulon in 1898. Fifty perennial 
species were selected, each plant being split in two, so that cultures of the 
same individual were conducted at Toulon and Fontainebleau. The plants 
used were obtained at Fontainebleau, while the soil for the parallel cultures 
was taken from Toulon. The external characters of the Toulon individuals 
were noted in the first communication ;7? these characters have been onl 
accentuated in the succeeding seasons, and the experimental plants have 
become quite like plants of the same species native about ) 
early secondary wood at Toulon contains vessels of larger caliber sic at 
Paris, while on the other hand the later wood is more fibrous at the former 
place. Again, in autumn the Toulon wood contains vessels of large caliber. 
Bonnier thinks that the large early and late vessels at Toulon are to be cor- 
related with the two rainy periods, while the fibrous wood of summer is cor- 
related with a dry period. Paris, on the other hand, has a more uniform 
climate, which is moister in summer than that of Toulon. The annual ring 
is thicker at Toulon. Many differences in leaf structure are also noted ; for 
the most part the Toulon leaf characters are the more xerophytic. 
immense importance of this type of study is obvious; it escapes on the one 
hand the errors arising from hasty field generalizations, and on the other 
hand it is free from the untenable inferences often drawn from experimental 
tr. GAZ. 30: 25-47. pls. 6-7. 1900. See review in Jour. Appl. Micros. 3: 
BOD 1900 
ONNIER, GASTON, Cultures expérimentales dans la région méditerranéenne 
pour le modifications de la structure anatomique. Compt. Rend. 135:1285-1289. 
go2 
7*Compt. Rend. 129: 1207-1213. 1899. 
