Mann.] 286 [September 1», 



Dr. Pickering said that the method of rubbing in a groove 

 was still in use in Tahiti, and he had seen fire obtained in 

 that way in about three minutes. 



September 18, 1867. 



The President in the chair. Thirty-five members present. 



Mr. H. Mann exhibited some capsules of Cyclanthera ex- 

 plodens or elastica, a Cucurbitaceous vine. 



He showed that they were monocarpellary fruits on exactly the 

 plan of one of the carpels of the cucumber, the placenta being in- 

 flexed to the dorsal side of the carpel, and the edges there thickened 

 and dilated, and bearing the seeds turned towards the ventral side; 

 only the thickened edges of the carpellary leaf acquu-ing a firm con- 

 sistency. This part of the placenta is firmly connected with the apex 

 of the ventral and convex side of the capsule, which, in dehiscing, 

 becomes violently torn away from the dorsal side, carrying with it 

 the placenta, and by the suddenness of the motion, flinging the seeds 

 to a distance of twenty or thirty feet. Mr. Mann said that he had 

 found a weight of five ounces insuflicient to straighten the backwardly 

 incurved ventral valve after dehiscence; more weight could not re- 

 main attached. In answer to a question of the President, Mr. 

 Mann said that the elastic power lay wholly in the thin outer 

 layer of cells, which were five or six times longer than their trans- 

 verse diameter, and thick walled. 



Mr. W. H. Niles ofiered some remarks upon the principle 

 of cephalization as applied to the classification of Echino- 

 derms. 



The term cephalization is applied to the relations of the head, or 

 anterior portion of the body, to the posterior portion, as a principle of 

 animal structure, exhibiting the relative rank of different groups of an- 

 imals. The more prominent and the more perfectly organized the head, 

 the higher the grade of cephalization and the higher the rank of the 

 animal. Cephalization thus becomes the principle of head or cephaUc- 

 domination, in the difierent forms of animal life. This principle has 

 been ably presented by Prof J. D. Dana, as it is embodied in the 

 higher groups of animals and in man. The remarks of Mr. Niles 



