May 5, 1899.] 



SCIENCE. 



653 



were also found upon yuccas. Mr. Ashmead 

 said that the Dasylirion insects were very simi- 

 lar in character to the insects found in decaying 

 palmetto in Florida. 



The next paper was by Mr. Marlatt, and in 

 the absence of the author was read by Mr. Ben- 

 ton. It was entitled ' Remarks on some recent 

 worli on Coccidse.' L. O. Howard, 



Secretary. 



THE WASHINGTON BOTANICAL CLUB. 



The fifth regular meeting of the Washington 

 Botanical Club was held April 5, 1899, at the 

 residence of Mr. Frederick V. Coville. 



Professor E. L. Greene made some remarks 

 on the occurrence of parthenogenesis in Anten- 

 naria, apropos of Juel's recently published in- 

 vestigations in A. alpina. He considered the 

 phenomenon to be well established in several of 

 our native species. 



Mr. J. G. Smith presented a synopsis of a 

 proposed revision of the genus Sitanion, a group 

 of grasses long included under Elymus. He 

 was able to segregate a large number of new 

 species, chiefly from Western localities. 



Mr. H. J. Webber gave some notes on the 

 various forms oi Zamia found in Florida. There 

 are apparently two well-marked species, at 

 least on the east coast, one confined to the 

 northern, the other to the southern half of the 

 State, while on the west coast occurs possibly a 

 third. Neither of these species is referable to 

 Z. integrifolia Jacq., a name under which the 

 plants have been described in most text-books. 

 Mr. Webber exhibited numerous photographs, 

 pointing out remarkable differences in the shape 

 and structure of the fertile spike. 



The Club extended invitations to the Phila- 

 delphia Botanical Club and to the Torrey Botan- 

 ical Club of New York to visit Washington for 

 a series of botanical excursions during the last 

 week in May. Charles Louis Pollard, 



Secretary. 



section op astronomy AND PHYSICS OF THE 

 NEW YORK ACADEMY OF SCIENCES. 



A MEETING of the Section was held on April 

 10th, Professor M. I. Pupin, the Chairman of 

 the Section, presiding. 



A paper was read by Dr. A. S. Chessin on 



' The Temperature of Gaseous Celestial Bodies.' 

 The author said, in brief, that, in view of some 

 extravagant and baseless assertions which have 

 appeared lately in both scientific and popular 

 periodicals with regard to certain supposed 

 laws of temperature in gaseous celestial bodies, 

 it seemed proper to state the true condition of 

 our knowledge in this direction. Dr. Chessin 

 showed that what Dr. See assumed, in a recent 

 article, to be a ' fundamental law' of nature, 

 namely, the formula RT = a constant, in which 

 T = the absolute temperature of the gaseous 

 body and R = the radius, was neither a ' fun- 

 damental' nor ' any law ' at all ; in fact, 

 the formula is the result of erroneous and 

 superficial calculations. Dr. Chessin also gave 

 an account of the work done by others on 

 the question of the temperature of heavenly 

 bodies, particularly referring to the investiga- 

 tions of A. Ritter, in Wiedemann's Annalen 

 for 1878. He showed how far from applicable 

 to actual facts most of these theoretical discus- 

 sions and calculations are, and he drew the 

 conclusion that at this stage of our knowledge 

 it would be but an idle speculation to formulate 

 any law which may govern the changes of tem- 

 perature in heavenly bodies. He called atten- 

 tion to one interesting case discussed by Ritter 

 in his theoretical investigations, a case in which 

 when y, or the ratio of the specific heat at con- 

 stant pressure to that at constant volume, is 

 greater than 4/3, we could have a pulsating 

 condition of the gaseous body about a condition 

 of equilibrium. A resume of Ritter's work ap- 

 pears in Exner's Repertorium for 1884. Betti, 

 of Pisa, has discussed the same problems and 

 obtained the same results. 



In the discussion Professor Pupin said that 

 in the contraction of a heavenly body the work 

 done by gravitation might be an excessively 

 small fraction of the total work done by all the 

 forces, including the so-called forces of chemical 

 affinity, which we usually consider are due to 

 electrical forces. But we cannot at present 

 base any calculations on these, as we know So 

 little about them. 



Professor Rees said that if astronomers can- 

 not yet solve these problems, it is because they 

 cannot get the proper knowledge from the 

 physicists on the physical parts of the question. 



