140 



SCIENCE. 



[N. S. Vol. XVI. No. 395. 



only one cotyledon develops. The en- 

 dosperm is peripheral. 



In Agrostemma Githago we find from one 

 to tlu*ee archesporial cells, one or two tapetal 

 cells and only two megaspore cells, of 

 which the lower develops into the sac. Fre- 

 quently two sacs begin to develop, but one 

 is always absorbed before the two-celled 

 stage is reached. The sac begins to enlarge 

 after the four-celled stage, the principal 

 enlargement being from the antipodal end 

 and at right angles to the long axis of the 

 sac. The antipodals persist for a short 

 time, but the synergids disappear early. 

 In the four-celled stage a zone of very thin 

 walled cells surrounds the sac and the ab- 

 sorption of these cells is an important fac- 

 tor in the enlargement of the sac. A long 

 beak is formed from the micropylar end of 

 the ovule. The formation of the embryo 

 is regular and the basal cell of the filament- 

 ous suspensor is very large. Both cotyle- 

 dons develop. The endosperm is periph- 

 eral. 



Studies in Phijcomyccte Fertilization: 



ScUrospora Graminicola (Sacc.) : F. L. 



Stevens, A. & M. College, W. Raleigh, 



N. C. 



The oosphere in Sderospora graminicola 

 is uninucleate, clearly resembling the gen- 

 eral type exhibited in the Peronosporeae 

 .and in Aliugo Candida, but differing from 

 the more primitive forms such as Albugo 

 dliti and A. Tragopogonis. The antheri- 

 dium bears several nuclei, but one only en- 

 ters the antheridial tube. Simultaneous 

 mitosis occurs here as in the related forms, 

 zonation is a prominent phase in oogenesis 

 and the coenocentrum is a conspicuous 

 organ in the oogoniiun. 



Notes on Agrostis: A. S. Hitchcock, U. S. 



Dept. of Agricultiu-e, Washington, D. C. 



Synonymy of species of the genus Ag- 

 rostis occurring in North American His- 



tory of several names. Notes on some of 

 the early species described by Triu and 

 others. 



TIte Absorption of Water; A Function of 

 the Ligule and Stipulaceous Tissue of the 

 Grasses: F. L. Stewart, Merrysville, Pa. 

 An account of observations and experi- 

 ments proving that, coordinate with certain 

 structural provisions for the conveyance 

 from the leaf-blade of the grasses of dew 

 and rainwater deposited thereon, the ligule 

 and the connected tissues of the leaf -sheath 

 actively absorb it and transmit it into the 

 circulatory system of the plant, thus sup- 

 plementing the supply of water derived 

 from the root. 



Tlie Pith Cells of Phytolacca Decandra: 

 Henry Kraemer, Philadelphia, Pa. 

 The pith of this plant is differentiated 

 into two parts, a peripheral portion made 

 up of active cells, and a central metamor- 

 phosed portion consisting of biconcave 

 diaphragms composed of both active and 

 inactive cells separated at regular intervals 

 by cavities. The latter appear to be formed 

 by the abstraction of water from the cells 

 of this region, as a result of the develop- 

 ment of other parts of the stem. This view 

 as to their origin seems to be confirmed by 

 the fact that in the process of drying that 

 portion of the pith in the upper internodes, 

 which is not already metamorphosed, be- 

 comes thus differentiated. The metamor- 

 phosed pith in Phytolacca decandra seems 

 on the one hand to have a certain resem- 

 blance in origin to the hollow internodes of 

 the stems of the Polygonaceae and on the 

 other hand to resemble the heterogeneous 

 or modified pith of the Magnoliaceae. 



A Review and Criticism of the Botanical 

 Curriculum of some of our Colleges and 

 Universities— from the Student's Stand- 

 point: E. IIead Wilcox, Auburn, Ala. 



