732 



SCIENCE. 



[N. S. Vol. IV. No. 



Britton and Brown's Illustrated Flora of the 

 Northern United States and Canada. 



Dr. Erwin F. Smith described a Bacterial 

 Disease of Potatoes, Tomatoes and Eggplants, 

 caused by a new micro-organism, Bacillus 

 solanaceanum, wbicb he believed to be the cause 

 of a large part of the potato rot of the United 

 States. Numerous infection experiments per- 

 formed in 1895 and repeated this year have set 

 the parasitic nature of the organism beyond 

 dispute. The following are some of the pecu- 

 liarities of this bacillus : Organism motile ; 

 forms zoogloea in liquid cultures ; does not 

 liquefy gelatin ; strictly serobic, does not pro- 

 duce any gas or any acid when grown in the 

 presence of sugars ; produces an abundance of 

 alkali (ammonia) in various media; develops a 

 decided brown pigment when grown in the 

 presence of various sugars (agar cultures, fer- 

 mentation tubes, potato cultures, etc.) ; grows 

 readily in the thermostat at 37° C. ; thermal 

 death point (ten minutes' exposure) about 52 °C. 

 The organism is probably transmitted from 

 diseased to healthy plants by means of insects. 

 In the greenhouse, under strict control condi- 

 tions, very successful infections have been ob- 

 tained by means of the Colorado potato beetle 

 {Doryphora 10-lineata). A bulletin giving a full 

 account of this parasite will soon be published 

 by the Division of Vegetable Physiology and 

 Pathology, U. S. Department of Agriculture. 



F. A. Lucas, 



Secretary. 



ENTOMOLOGICAL SOCIETY OP WASHINGTON, 

 OCTOBER 8, 1896. 



The President announced the death of Mr. 

 Henry F. Schonborn, a Washington entomolo- 

 gist, who possessed the largest private collec- 

 tion of Lepidoptera in the city. 



Mr. Ashmead exhibited a female specimen of 

 the family Thynnidse which he had found in the 

 National Museum collection labelled ' Alameda 

 County, California. ' This is the second North 

 American species of this family recorded from 

 America. Mr. Ashmead will call it Glyptometopa 

 americana. Some discussion ensued and it was 

 suggested that both species had been accident- 

 ally imported into America. 



Mr. Heidemann exhibited a drawing of the 



winged male of Bheumatobates rileyi, showing 

 that the description of the species must now be 

 revised. 



Mr. F, C. Pratt exhibited specimens of the 

 spine-like cases of Coleophora octagonella, taken 

 from orange, and which exactly resembled the 

 thorns of orange. 



Mr. Hubbard presented a preliminary notice 

 of a new Coccid on birch from the Lake 

 Superior region. This insect is very abundant 

 and causes the general destruction of the bark 

 of birch trees, so much so that it is difficult to 

 find near the Lake a tree of any size with 

 smooth or natural bark. The outer bark is 

 roughened, covered with curls and splits, 

 blackened with sooty mold, and in bad cases 

 entirely removed down to the last layer. 

 Often the cambium itself is invaded and the 

 tree is killed or seriously injured. The young 

 larva of the Coccid crawls into the lenticels of 

 the bark and, growing and forming thick 

 masses of wax, causes the bark to heave and 

 layers to separate in curls. He had studied the 

 development of the species, which exhibited 

 several remarkable features. The female under- 

 goes three molts and has four stages, of which 

 the larva and adult are active and possess legs 

 and antennae. The two intervening stages are 

 stationary and degraded. The author con- 

 siders the species to belong in all probability to 

 the genus Xylococcus. 



Dr. M. G. Motter presented a paper entitled 

 'A Contribution to the Study of some Necro- 

 phagous Diptera,' giving a preliminary an- 

 nouncement of some results of his study of the 

 fauna of cadavers which he has been carrying 

 on for some months with a view of substantiat- 

 ing or contradicting conclusions of Megnin and 

 other writers. L. O. Howard, 



Secretary. 



NORTHWESTERN UNIVERSITY SCIENCE CLUB. 



At the first meeting of the college year, 

 October 9th, Dr. Marcy in the chair and eighteen 

 persons present. Prof. Young presented for the 

 department of chemistry ' Notes on the De- 

 velopment of Explosives, ' in which he reviewed 

 the processes of explosion and the nature and 

 use of explosives. A. E. Crook, 



Secretary. 



