1894.] rafter — use of concrete for storacie dam. 293 



June 25, 1894. .; 



stated meeting. 

 The President, Professor H. L. Fairchild, in the chair. 

 Forty-seven persons present. 

 The following paper was presented : 



ON THE USE OF CONCRETE FOR THE PROPOSED STOR- 

 AGE DAM AT MOUNT MORRIS. 



By George W. Rafter. 



After some remarks upon the matter of Mr. Rafter's paper, the 

 President stated that the remainder of the meeting would be held 

 under the direction of the Botanical Section, as had been announced 

 upon the notices of the meeting. The President then yielded the 

 chair to the Chairman of the Section, Miss Mary E. Macauley. 



The first paper announced on the printed program was read for 

 the author by the Recorder of the Section, Mrs. J. H. McGuire, as 

 follows : 



ON VOLVOX GLOBATOR. 

 By a. M. Dumond. 



These beautiful forms forcibly remind me of the ancient Egyp- 

 tian symbol of life, a flying globe, and may it not be that that wonder- 

 ful people, away back in the dim ages of the past, knew and studied 

 this interesting form? Volvox gl abator, when fully grown, varies from 

 sV ^o "fV of ^" ^'^^^'^ ^'^ diameter. It is a colony, composed of thous- 

 ands of cells called gonidia, so grouped together that they form a 

 hollow sphere, the inner surface of which is studded with thousands 

 of green points, while the outer surface has the appearance of a nearly 

 transparent globe composed of hexagonal cells, bound together by a 

 net-work of wonderful beauty ; each of the hexagonal cells, or goni- 

 dia, of which there are several thousand, is, when free, a somewhat 

 pear-shaped cell, about -g^Vir of ^'^ i"ch in diameter, containing chlor- 

 ophyl grains and with traces of starch diffused through its protoplas- 

 mic contents. 



A red spot is also usually perceptible, which is generally believed 

 to consist of altered chlorophyl. From the small end of this pear- 

 shaped cell project two cilia, which are evidently a portion of the 



