Febbuary 9, 1906.] 



SCIENCE. 



203 



giving the plant societies and conformation 



of the surface. 



The Development of Armillaria mellea; 



The Development of Agariciis campes- 



tris: Geo. F. Atkinson. 



These papers described the development 

 of the sporocarps from the homogeneous 

 condition up to the differentiation of the 

 parts of the mature structure. 



The Behavior of the Pollen Tube in Hous- 

 tonia coerulea: Chester A. Mathewson. 

 The ovules of this plant are without in- 

 tegument and there is therefore no micro- 

 pyle. The course of the pollen tube is 

 analogous to that described by Lloyd for 

 other Rubiaceae. It follows the style as 

 far as the basal element of the ovary parti- 

 tion. Here it enters the tissue of the pla- 

 centa stalk, and following this it enters the 

 placenta. It reaches the ovule through 

 the funicle and is then directed to the egg 

 end of the embryo sac. 



Hing Formation in Artificial Cultures: 



George C. Hedgcock. 



Further studies have been made of the 

 formation of fruiting rings in artificial 

 cultures on agar media of Cephalotheciiim 

 and Penicillium, and the same character 

 noted in cultures of other fiingi. Cultures 

 were grown in the dark, and in ordinary 

 light, establishing that the type of forma- 

 tion studied occurs only under the influence 

 of light. Next, cultures were grown under 

 rays of light transmitted through solutions 

 "of orange, red, blue and green in addition 

 to the previous conditions. Under the 

 effect of blue rays and in the dark no rings 

 were formed, while rings were formed 

 under the other conditions. The rings 

 formed consist of alternating daily masses 

 of denser spore formation. Daily fruit 

 rings were observed with cultures of Mucor 

 and Hormodendron, in addition to those 

 already reported. These rings must not 

 be confused with those of the type de- 



scribed by Milburn on certain kinds of 

 media with Hypocrea rufa, since the latter 

 were not formed daily, each occurring dur- 

 ing a much longer period. 

 Notes on the Morphology and Embryology 



of the NympheacecE : Mel. T. Cook. 

 As a result of the recent work of Conard 

 and others the writer has again taken up 

 the study of this family, using Cuban ma- 

 terial for the work. Members of the genus 

 Nymphcea correspond with the writer's 

 previous work upon this group. Members 

 of the genus Castalia show some differences 

 in that the embryo sac is not so long and 

 the embryo has a suspensor. Members of 

 the genera Bracenia and Cabomba corre- 

 spond with Nymphcea in the enlargement 

 of the embryo sac. All embryos show 

 monocotyl characters, but some show char- 

 acters similar to those of dicotyls. . The 

 Cuban species of Castalia show more 

 striking dieotyl characters than our north- 

 ern species. 

 North American Species of Peridermium: 



J. C. Arthur and F. D. Kern. 



This paper dealt with certain fungi 

 growing on the leaves of various coniferous 

 trees, and sometimes on the limbs. A half 

 dozen kinds form large swellings on the 

 branches and trunks of pines and do much 

 injury, not only decreasing their value for 

 lumber, but ruining small trees in nur- 

 series. Altogether twenty-six species are 

 described, a number of them being new. 

 Stomatal Action ' and Transpiration in 



Fouquieria splendens and Verbena cili- 



ata: F. B. Lloyd. 



The •'evidence derived from the compara- 

 tive study of these two types leads to the 

 conclusion that there is no close coi'relation 

 between transpiration and stomatal action. 

 The maximum opening of stomata is 

 reached some hours earlier than the maxi- 

 mum of transpiration, and, further, wide 

 variations in the rate of transpiration may 

 take place without any change in the size 



