318 BOTANICAL GAZETTE [ocToBER 
in the endosperm and integuments during seed development; and (2) with 
reviews of various papers dealing with different methods of embryo sac nutrition. 
While Lonco’s paper was in press, that of Kirkwoop" appeared. A footnote 
by Lonco states that his observations and Kirkwoop’s do not agree in respect 
to the presence of a micropyle and the passage of the pollen tube through it in 
Cucurbito Pepo. Lonco maintains that in this species no micropylar canal is 
present, but that the pollen tube grows between the cells of the nucellus. Asa 
‘micropyle is present in other species, he thinks Ktrkwoop: has made a mistake 
in determination.—F. H. Brtirncs. 
Two INVESTIGATORS have published preliminary announcements of the 
results of a study of fertilization and the associated structures in Jumiperus com- 
munis. NoréN*S says that during the summer following pollination the pollen 
_ tube grows into the tissues of the nucellus, but fertilization does not occur until 
the following year. The two male cells are equal in size. A ventral canal 
nucleus is formed, but it is not separated from the egg by a wall. The male cel 
is still surrounded by its cytoplasm when it enters the egg, but slips out from it 
as the sex nuclei come into contact. There are eight free nuclei in the proembryo 
‘before walls begin to be formed. 
SLUDSKY’s'® announcement was hastened by that of NorEN. He —_ 
that the entire development of the sexual generation, from pollen to fertilization, 
and from megaspore to embryo, lasts only one summer; the growth of the pollen 
tube lasting only two to six weeks. A ventral canal nucleus is formed, but dis- 
appears before fertilization. Centers with radiations are prominent In the As" 
and are caused by the diminishing pressure which accompanies the formation ° 
vacuoles. There are never more than two male cells in a pollen tube. — 
cellular complex described for Cupressus by JUEL is regarded as te 
material. Not more than two male cells ever enter the egg, and only bes funct 
in fertilization. The nucleus of the male cell is still surrounded by 1s cytof | 
after it enters the egg. During fertilization there can be seen in the upper Pas 
of the egg the tube nucleus, neck cells, and even cells of the overlying me 
In regard to the fusion of sex nuclei, the author agrees with NorEN, and in 
to the embryo he agrees with SrRASBURGER.—C. J. CHAMBERLAIN. ; 
LILIENFELD"? ascribes the indecisive results obtained by aie”: s 
Ruopes in their study of the chemotropism of roots to inadequate tions (1) 
Among the sources of error unprovided for by them the author men 
14 KirKwoop, I. E., The comparative embryology of the Cucurbitaceat 
in Bor. GAZETTE 39:73. 1905. i Vorlaufige 
sNoréx, C. O., Ucber Befruchtung bei Juniperus commun 
Mitteilung. Arkiv. Bot. Svensk. Vetens. Akad. 3: pp- 11- 1994 P commis 
16 SLupsky, N., Ueber die Entwickelungsgeschichte des Juniperus 
Vorlaufige Mitteilung. Ber. Deutsch. Bot. Gesells. 23: 212-216. 
17 LILIENFELD, M., Ueber den Chemotropismus der Wurzel. 
Bot. Gesells. 23:91-96. 1905. 
Ber. 
