300 



SCIENCE. 



[N. S. Vol. XI. No. 269. 



good when the nodes were placed at angles 

 below the horizontal position. Young 

 nodes show a definite response to geotropic 

 stimulus when exposed for so short a period 

 as 30 seconds. The latent period is about 

 30 minutes long. 



On the embryo sac of Saururus cernuus : De. 

 D. S. Johnson, Johns Hopkins Univer- 

 sity. 



The development of the bract and flower 

 is essentially like that found in the Piper- 

 acese by Schmitz. In the material studied 

 there were two ovules to each carpel, of 

 which only one, the upper one, matured to 

 a seed. There are two integuments as in 

 most of the Piperacese and both grow up to 

 form the micropyle. The primary arches- 

 porial cell is single and hypodermal in posi- 

 tion. It divides to a definite. archesporial 

 cell and an upper tapetal cell. The former 

 then divides to three potential macrospores, 

 of which the lower only becomes functional. 

 This grows and the nucleus divides in the 

 usual way to form a seven nucleate embryo 

 sac. The embryo sac soon widens at the 

 base to become flask-shaped, with the egg 

 apparatus at the upper end of the neck and 

 one endosperm nucleus in the neck and 

 probably a second one in the body of the 

 flask. The antipodals soon become indis- 

 tinguishable, probably degenerating. En- 

 dosperm cells are formed in the neck of the 

 flask before any change can be seen in the 

 egg itself. In the ripe seed the endosperm 

 is found to have swelled laterally using up 

 only the tip of the large nucellus while the 

 lower or body end of the embryo sac is 

 still without endosperm cells or nuclei. 

 The features of the development of Saururus 

 thus far studied give no conclusive evidence 

 of its primitive character. 



Upon the best way of securing a good revieiv of 

 Current Botanical Literature : Professor 

 W. G. Farlow, Harvard University. 

 Professor Farlow 's address upon this 



subject appeared in synopsis in the Botan- 

 ical Gazette for January. He pointed out 

 that this is a question distinct from that of 

 a card catalogue, international or other, of 

 literature. None of the existent journals 

 fully meets the needs of botanists for prompt 

 descriptive synoptic reviews of current lit- 

 erature. The Botanisches Centralblatt comes 

 the nearest to the needed journal, and if 

 its reviews were more prompt, and, in 

 many cases, of a more descriptive character, 

 and if it did not take up with original 

 articles so much space which ought to be 

 given to reviews, thus forcing many of the 

 latter into Beihefte for which an additional 

 subscription must be paid, it would be much 

 more satisfactory. The discussion follow- 

 ing this paper showed that similar opinions 

 are held generally by botanists in this 

 country, and steps were taken to communi- 

 cate the Society's opinions upon the subject 

 to the editors of the Centralblatt. 



Fasciation in the Sweet Potato : Mr. Henry 

 S. CoNAED, University of Pennsylvania. 

 (By invitation.) 



The author stated that typical fascia- 

 tions J in. to 3 in. broad are common in the 

 sweet potato. The internal structure of 

 these diifers from that of normal stems only 

 in the shape of the cross-section. On poor 

 soil 12% of the stems are abnormal, on 

 good soil 18% ; counting apices only, 20% 

 are abnormal on poor soil, 54% on good 

 soil. Of the abnormal stems \% to 1% are 

 ring-fasciated. Such stems enlarge grad- 

 ually from the base, but maintain a round 

 cross-section. They become hollow within, 

 the cavity opening to the air at the growing 

 apex. The apex has a wavy margin ; or 

 the tube may be split above, and may give 

 rise to plain fasciation. The tubular por- 

 tion may be as much as 2 or 3 ft. long by |- 

 to f in. in diameter. The cavity has on its 

 walls acropetally developed leaves, and ad- 

 ventitious roots ; the latter become func- 



