cxlviii 



there is no intermission in the appearance of the winged females from the 

 middle of July till frost, but the increase reaches its acme the latter part of 

 August. 



He found it very difficult to obtain the sexual individuals, as, though 

 the winged insects delivered themselves of their eggs with the greatest 

 ease, attaching them in clusters to the sides of tubes or jars in which they 

 were contained, or pushing them into the tomentose portions of the vine, 

 or into crevices in the earth; yet the eggs generally failed to hatch, and 

 the embryo perished most often when just at the point of hatching and 

 when sufficiently developed to show its character. He had, however, suc- 

 ceeded in hatching two males, and had been much more fortunate with the 

 American oak species. 



He had recently received a letter from M.J. Lichtenstein of Montpellier, 

 France, in which that enthusiastic entomologist made the astounding an- 

 nouncement of having discovered that Phylloxera vastatrix, in the winged 

 form, congregates and swarms on the leaves of the Chermes oak {^uercus 

 cocciferd)^ which it uses as a nidus for its eggs. Mr. Riley stated that with 

 all his faith in M. Lichtenstein's knowledge of Phylloxera, he was forced 

 to the conclusion that some other species had been confounded with vasta- 

 trix, and microscopic examination of specimens of the sexed individuals 

 kindly sent by Lichtenstein only confirmed him in the opinion. It was, 

 therefore, with no little interest that he noticed, from the abstracts given 

 in Nature of the doings of the Paris Academy of Science, that Balbiani 

 considered the species found on ^. coccifera as distinct from vastatrix, 

 and proposed to call it Lichtensteinii. 



Dr. Engelmann exhibited a section of the trunk of yuniperus 

 Californica^ var. Utahensis, which was not quite 4 inches in 

 diameter and yet showed an unmistakable age of 127 years, each 

 ring being on an average about ^ of a line wide. The largest 

 growth in 10 years had been about 4 lines, the smallest in 10 

 years about x\ lines. It was one of the most remaikable instances 

 of slow growth that had come to his notice. 



November 2, 1874. 

 W. T. Harris, President, in the chair. 



Fifteen members present. 



Several communications were read by the Corresponding Secre- 

 tary, who was instructed to send the Transactions, from vol. iii. 

 No. I, to the Rantoul Literary Society, Rantoul, Ills. 



The following communication, from Mr. Amos Sawyer, was 

 read and ordered incorporated in the minutes : 



