28 BIOLOGICAL SOCIETY OF WASHINGTON. 



• 

 Seaman referred to the climbing organs of the Virginia creeper, 



Ampclopsis quinquefolia, and of the so called "suckers" of various 

 sea-weeds, which though perhaps not suctorial in action seem to 

 cling to objects in a manner which is similar to suctorialism. Prof. 

 Riley spoke of a suctorial organ of prehension in the thoracic proleg 

 and anal pseudopod of Simulium larva; and to the ventral branchiae 

 of the helgramite or dobson, Corydalis cornutus, larva, which are 

 suctorial in function. Prof. Gill, speaking of the suctorial powers 

 of young marsupiates stated that he believed them to exert an actual 

 suctorial power, even though the teats be somewhat modified to aid 

 them in clinging. Their first attachment to the teat is purely suc- 

 torial, though afterward probably the result of a spasm-like action 

 of the sphincter-oris muscle. He also referred to the suctorial 

 organs possessed by certain bats. Mr. Patton called attention to 

 the peculiar structure of the larva of Blcpharocera which inhabits tor- 

 rents and has six segments, each provided with a separate suctorial 

 organ, probably prehensive. 



Dr. A. F. A. King read a paper entitled Septenary Periodicity in 

 Living Organisms ; in the discussion of which Messrs. Prentiss, 

 Riley, Scudder, Ward, and many others participated. 



Ninth Meeting, March 25, 1881. 



The President occupied the chair, and thirty-five members were 

 present. 



Col. Marshall McDonald read a communication On the Laws of 

 the Relation of Periodicity in Development to Temperature. 

 This paper was discussed by Messrs. Prentiss, King, Busey, Gill 

 and Chickering. 



Prof. J. W. Chickering, Jr., read a paper entitled Roan Moun- 

 tain and its Flora.* 



Prof. J. E. Todd read a paper entitled On the Flowering of 

 Solanum rostratum, and Cassia cHAM^cRisTA.f 



*See 1S82. Chickering, John W., Jr. Notes on Roan Mountain, North 

 Carolina. < Bulletin, Philosophical Society of Washington. IW- 1881. pp. 

 60-64. (Flora, p. 63). 



-J-18S2. Todd, Tames E. On the Flowers of Solanum rostratum, and 

 Cassia chamacrista. < American Naturalist. XVI, 18S2. (April), pp. 281- 

 287. 



