886 



SCIENCE. 



[N. S. Vol. XII. No. 310. 



TOEREY BOTANICAIi CLUB. 



At the meeting of the Club on October 31st, 

 Dr. P. A. Rydberg read a paper on ' The Me- 

 lanthacese of the Eocky Mountains.' Numer- 

 ous herbarium specimens were exhibited, in- 

 cluding the types of seven new species described 

 by Dr. Rydberg in the Torrey Bulletin for Oc- 

 tober. To these descriptions he now added 

 further particulars regarding habit, distribution 

 and critical characters, presenting also a series 

 of comparative drawings of their petals and 

 sepals. One of these new species of especial 

 interest is Veratrum speciosum, to which most of 

 the specimens previously ascribed in herbaria 

 to V. Californicum prove to belong. The pres- 

 ence of conspicuous petioles at the lower leaves 

 of typical V. Californicum was demonstrated 

 from the type-specimen and also by explicit 

 accompanying statements by Dr. Asa Gray, 

 whose manuscript description was produced. 

 Edward S. Burgess, 



Secretary. 



ZOOLOGICAL JOURNAL CLUB OF THE UNIVER- 

 SITY OF MICHIGAN. 



The first meeting of the club was held No- 

 vember 1st. Dr. S. J. Holmes reported the re- 

 sults of work done at Woods Holl during the 

 past summer on the habits and natural history 

 of Amphithoe longimana Smith. The observa- 

 tions made were upon the movements of the 

 animal, food, nest-building and instincts asso- 

 ciated with living in nests, moulting, color 

 changes, the seat of smell and the instincts of 

 the young. 



Mr. L. J. Cole gave an account of work done 

 at Woods Holl during the past summer on the 

 habits of Pycnogonids. Most of the notes were 

 based on observations of Anoplodactylus, though 

 Tanystylum and Pallene were studied also. 



Crawling and Swimming Movements. — The ac- 

 tion of the legs in crawling and in swimming 

 was analyzed and was found to be exactly the 

 same in the two cases. When the stroke of the 

 legs is strong enough to lift the animal from 

 the bottom, swimming results ; otherwise the 

 same movement produces crawling along the 

 bottom. The stroke of all the legs is the same 

 except that it is stronger in the anterior legs, 

 and this is what carries the animal forward in 



crawling, rather than backward. The action of 

 the posterior legs is an actual hindrance in 

 crawling. 



Reactions to Light. — 1. Both Anoplodactylus 

 and Pallene show strong positive phototaxis. 

 In going towards the source of light Anoplo- 

 dactylus may either crawl or swim, being ori- 

 ented differently in the two cases : 



2. In crawling towards the light the animal 

 progresses forward. If not oriented in this di- 

 rection at first it becomes so oriented by making 

 a short circle in every case towards the light. 



3. When an animal walks in a circle those 

 legs on the outside must make a more eflfective 

 stroke than those on the inside, which means in 

 this case that those legs away from the light beat 

 stronger than those towards the light. 



4. In swimming towards the light the animal 

 progresses approximately backward with the 

 anterior end somewhat raised, the amount de- 

 pending upon the activity of the individual 

 and the slant of the rays of light. 



5. This orientation is brought about by the 

 actions previously mentioned : (a) The stronger 

 action of the legs on the side away from the 

 light raises that side, and the animal conse- 

 quently travels toward the light ; (6) The 

 stronger action of the anterior legs, as compared 

 with that of the posterior, tends to bring the 

 anterior end of the animal into the upper posi- 

 tion, giving the orientation described. 



Transfer of the Eggs from the female to the 

 ovigerous legs of the male. — ^When first ob- 

 served the male was clinging to the dorsal sur- 

 face of the female and headed in the same 

 direction. The basal joints of the legs of the 

 female were approximated below with a mass 

 of eggs between. The male crawled around 

 over the anterior end of the female, coming 

 into such a position that their ventral surfaces 

 were together and their heads in opposite direc- 

 tions. The ovigerous legs of the male hooked 

 into the mass of eggs, and as the animals sep- 

 arated carried them away. Fertilization pre- 

 sumably took place at the same time. 



At the second meeting, November 8th, Dr. 

 S. J. Holmes presented an account of work 

 done during the past summer at Woods Holl 

 on Phototaxis in Amphipods. 



Most of the experiments were performed on 



