124 



SCIENCE 



[N. S. Vol. XLV. No. 1153 



c.c. was used nearly filled -witli water and a 

 uniform layer of medium-sized crystals placed 

 on an iron gauze shelf midway between tlie 

 bottom and the surface of the water. Any 

 change of absorption was noted as the crystals 

 went into solution. Slight changes took place 

 as the material dissolved and went to the bot- 

 tom, yet after a thorough stirring when solu- 

 tion was complete the readings of the electro- 

 scope returned to almost the initial value. A 

 small decrease in absorption was noted, how- 

 ever, in the majority of the experiments. 



It is hoped to repeat these experiments for 

 mercury and solutions, using more refined 

 apparatus and methods, and to study the effect 

 of crystalline structure on reflection by an 

 examination of changes in absorption for sub- 

 stances of high molecular weight which crys- 

 tallize in two forms such as lead nitrate, mer- 

 cury perchloride and mercury iodide. 



In conclusion I wish to express my indebt- 

 edness to Professor Sir Ernest Eutherford for 

 suggesting this general field of research; also 

 to Dr. Ernest Marsden for many helpful ideas. 

 P. B. Perkins 



BEOWN UNrVBESITT 



SOCIETIES AND ACADEMIES 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 561st meeting of the society was held in 

 the Assembly Hall of the Cosmos Club, Saturday, 

 December 2, 1916, called to order by President 

 Hay at 8 p.m., with 50 persons in attendance. 



The following program was rendered: 

 The Discovery of an Interesting New Tardigrade: 



W. P. Hat. 



Professor Hay gave a brief description of a 

 tardigrade belonging to the genus BatilUpes dis- 

 covered by him some years ago at Beaufort, N. G. 

 It is closely related to B. mirus Eiehters but dif- 

 fers from that species in a number of important 

 characters. 



The structure and relationship of the tardi- 

 grades was discussed and the conclusion was 

 reached that BatilUpes, in spite of its evident spe- 

 cialization along certain lines, is probably the 

 most primitive genus of the group. 



From BatilUpes through Ealecliiniscus to 

 Oreella and EcMniscus was suggested as one line 

 of development, while from EcMniscoides through 

 Milnesium to Macrohiotus and Diphascon appears 



to be another. The genus TetraTcentron with its 

 single species T. synaptce- shows a high degree of 

 specialization due to parasitism and Microlyda is 

 probably the larval form of Salechiniscus. 



Attention was called to the habitat of the bear 

 animalcules belonging to these genera. Five of 

 them, BatilUpes, HalecMniscus, Microlyda, Tetra- 

 Tcentron and Echiimcoides are marine. Ecliiniscus 

 and Oreella are strictly terrestrial. Macrohiotus 

 is mostly terrestrial or lacustrine but is repre- 

 sented in salt water by at least two species. 

 Diphascon is terrestrial and lacustrine. 



The fact that the majority of the genera are 

 marine and that this list includes all the more 

 primitive genera points strongly to a marine origin 

 for the group. It also supports the idea advanced 

 by Professor Eiehters in 1909 that the tardigrades 

 are probably most closely related to the chstopod 

 worms and should be removed from the class 

 Arachnida in, or near, which the group is usually 

 placed in our zoological text-books. 



Professor Hay's communication was illustrated 

 by charts and diagrams. 

 Exhibition of Venezuelan Plants and Fruits: J. N. 



EOSE. 



Dr. Eose had on exhibition a large table full of 

 fruits, fruit products and various articles made of 

 parts of Venezuelan plants. He explained their 

 usage and described the plants from which they 

 were obtained. The specimens were obtained for 

 the most part in the vicinity of La Guaira and Car- 

 acas. Dr. Eose's communication was discussed by 

 Messrs. H. Pittier, M. W. Lyon, Jr., and others. 

 Poisonous SnaTces: M. W. Lyon, Jr. 



Dr. Lyon gave an account of the various specific 

 substances that have been found in snake venoms, 

 and outlined their modes of action on the various 

 tissues of bitten animals. He spoke of the various 

 antiserums that have been prepared against these 

 venoms, and their therapeutic uses. He also called 

 attention to the non-specific treatment of snake- 

 bites in the light of modern statistics and experi- 

 ments. He then gave a brief outline of the classi- 

 fication of venomous snakes, their geographic dis- 

 tribution, of the development and structure of the 

 poison gland and fang. His communication was 

 illustrated by lantern slide views of skulls, glands 

 and fangs of poisonous snakes, of types of poison- 

 ous snakes and of some of the histological changes 

 caused by snake venom. This communication was 

 discussed by Messrs. A. A. Doolittle, H. Pittier,. 

 H. M. Smith, H. E. Ames and T. E. Wilcox. 

 M. W. Lyon, Je., 

 Recording Secretary 



