698 



SCIENCE. 



[N. S. Vol. VIII. No. 203. 



groups, which are perhaps the most diffi- 

 cult to segregate, have several iuteresting 

 forms. This paper attempts to characterize 

 the forms of Salix glauca L. and 8. grcen- 

 landica. 



A Self-registering Transpiration Machine. Ed- 

 win B. COPELAND. 



Description of a very simple and easily 

 operated apparatus, consisting of a wheel 

 over which runs a string carrying the plant 

 tested on one end and an areometer on the 

 other. As the plant loses weight, the coun- 

 ter weight, the areometer sinks. The rec- 

 ord is kept as with an auxanometer. One 

 day's record was presented to illustrate the 

 working of the machine. To be published 

 in The Botanical Gazette. 



Methods of Studying the Sap Pressure of the Sugar 

 Maple. Peofessoe L. R. Jones. 

 After some unsatisfactory experiments 

 with the common mercurial gauge, a self- 

 recording steam-pressure gauge (which was 

 exhibited) was substituted with very good 

 results. Lithium passed upward and down- 

 ward in the maples very rapidly, but there 

 was very little sidewise movement of this 

 substance. 



Notes on the Physiology of the Sporophyte of 



Funaria and Mnium. Dr. Rodney H. 



True. 



The growth rate of the sporophj'te of these 

 mosses may be represented by a rather flat 

 curve rising somewhat more gradually than 

 it falls. Subsequent to the breaking loose 

 of the calj'ptra from the gametophyte> 

 growth is confined to the distal end of the 

 sporophyte, and the growing region, about 

 2 mm. long, is entirely enclosed by the 

 calyptra. 



The calyptra, much developed in Funaria, 

 less so in Mnium, is a protective structure 

 chiefly useful in preventing desiccation. In 

 Funaria the cells of the calyptra are living 

 and contain chlorophyll grains. They are 



probably self-supporting as regards nutri- 

 tion until the rupture of the calyptra. 



The curvature of the seta in this species 

 results as a response to the stimulus of 

 gravitation. In the earlier stages of its 

 growth the seta is not sensible to this stim- 

 ulus, but becomes so as the time for the de- 

 velopment of the capsule approaches, and 

 by use of the mechanism of growth executes 

 the curvature. 



The direction of the strongest illumination 

 determines the radius in which the capsule 

 shall fall. In Mnium the capsule falls with 

 great regularity away from the direction of 

 the strongest illumination, thus exposing the 

 end of the capsule bearing the stomata to 

 the light. Occasionally some fall directly 

 toward the strongest light, but very rarely 

 out of that plane. 



Funaria obeys, with much less precision 

 and regularity, the same rule. The conduct 

 of these mosses varies in accordance with 

 the nature of the situations which they are 

 wont to occupy. 



Tlie Seeds and Seedlings of some Amentiferae. 



W. W. RowLEE and Geo. T. Hastings. 



As compared with the other groups of 

 angiosperms the Amentiferae have been, so 

 far as their seeds and seedlings are con- 

 cerned, very indiiferently observed. Find- 

 ing this to be true led the authors of this 

 paper to grow seedlings of the native repre- 

 sentatives of the group. Their studies have 

 led to the following conclusions : 1. The 

 cotj^ledons in Juglans and Hicoria corre- 

 spond with the valves of the nut, and are 

 deeply two lobed. The two divisions of the 

 embryo resembling cotyledons are each 

 made up of halves of the cotyledons. 2. 

 The seeds of Hicoria germinate without 

 frost action ; those of Juglans only with 

 frost action. 3. The tap-root is very 

 thick in young seedlings, and very long in 

 in older ones. 4. In Castanea and Quercm 

 the shell is split by a swelling of the coty- 



