214 THE AMEKICAN MONTHLY [September, 



Later in the day they descend to the ground in search of food, and again 

 toward evening, or about 5 o'clock, they resume their position on fences, 

 outbuildings, or anything on which they can perch. 



Mr. Ehrhorn carefully noted the habits and peculiarities of this Thy- 

 reotiotus^ and several very fine specimens of both male and female 

 served to illustrate his remarks. The eggs, he says, are deposited in 

 very hard ground, at a depth of about one inch below the surface, the 

 female working for hours to prepare a receptacle. The number of eggs 

 deposited by each female is from thirty to fifty. Like other species of 

 grasshopper their appearance in very large numbers in a locality seems 

 to be the result of favorable climatic conditions. Last winter being 

 a very mild one in Siskiyou county, the eggs were not destroyed by the 

 frosts, as they frequently are, and consequently nearly all hatched out 

 last spring. Although countless millions of eggs are now being de- 

 posited, should next v/inter be a severe one, so large a proportion would 

 be destroyed by the frosts that the grasshoppers would be scarce. 



Mr. Riedy exhibited a new projection lantern last evening, designed 

 for educational rather than exhibition purposes. It is provided with 

 an oil lamp, instead of the oxy-hydrogen burner usually employed, and 

 while the volume of light was not intense, it illuminated some objects 

 through the microscope quite successfully. The ordinary lantern lens, 

 with suitably-prepared slides, gave excellent results. 



August §^ i8gi. — President Wickson in the chair. After the read- 

 ing of the minutes, R. W. Baum, M. D., was elected to regular mem- 

 bership, and two applications were received, which took the usual 

 course. 



The committee appointed to consider the desirability of holding a 

 series of public receptions, reported in favor of changing the character- 

 of the meetijigs of the society, making the first meeting in each month 

 one of business and the reception of such papers as might come before 

 it, and the second meeting in each month in the nature of a conversa- 

 zione. It is further intended to make each alternate conversazione a 

 public one, to the limit of the society's rooms, invitations to be issued 

 by the committee. The suggestions were adopted in their entirety, 

 and the committee was made a Committee of Arrangements, to con- 

 tinue in office until the close of the society's fiscal year in February 

 next. 



The paper of the evening was readby Dr. M. C. O'Toole, on " Em- 

 bryology and Reproduction," a subject which has had his closest atten- 

 tion and most careful study for years. By way of introduction he 

 traced the recorded observations and theories on this interesting branch 

 of biology from the time of Democratus, in the fifth century before the 

 Christian era, to die present. Aristotle taught at Athens two centuries 

 later theories on this subject which, considering the time in which he 

 lived, may be looked upon as simply marvellous, if not prophetic. His 

 views differed very generally from all naturalists who had preceded 

 him and from those who followed for the next two thousand years. 

 Viewed in the light thrown on the subject by modern investigation, by 

 the aid of the microscope, it is now seen how exact were all his con- 

 clusions. 



In recent years biologists have been actively engaged in the study of 

 comparative embryology, and the knowledge thus gained has solved 



