Febkuaey 20, 1903.] 



SCIENCE. 



309 



studying sucli material to determine the course 

 of evolution in the home-building and social 

 habits of some of the bark and wood dwellers. 

 The various forms of the Scolytid gallery were 

 displayed, ranging from the simpler types to 

 the more specialized and symmetrical forms, 

 and charts were exhibited indicating the nat- 

 ural classification of the galleries and how 

 they correspond with the natural classification 

 of the insects. 



Under the title ' Evolution, Cytology and 

 Mendel's Laws,' Mr. 0. F. Cook noticed the 

 recently published theory that Mendel's laws 

 of the dissociation of parental characters in 

 hybrids are to be explained by the segregation 

 of paternal and maternal chromosomes at the 

 ' reducing division ' which precedes the for- 

 mation of the germ-cells. It was pointed out 

 that this theory is definitely disproved by the 

 very facts which it was intended to explain, 

 since the experiments of Mendel, Spillman and 

 others have shown that the characters derived 

 from different parents may enter into any 

 combinations possible under the law of chance. 

 The germ-cells may be said to be pure in 

 characters but not in parentage. It was 

 further argued that the existence of the ' he- 

 reditary mechanism ' sought by cytologists is 

 highly ibiprobable, and that heredity is not 

 the function of an organ, but a general prop- 

 erty of organisms, to be associated with crys- 

 tallization and with memory. The facts dis- 

 covered by Mendel should not be made the 

 basis of a separate generalization, since they 

 characterize but one of four kinds of ' hybrids ' 

 represejiting as many different evolutionary 

 stages. F. A. Lucas. 



GEOLOGICAL SOCIETY OF WASHINGTON. 



At the 137th meeting of the society, held 

 in the assembly hall of the Cosmos Club, 

 Wednesday evening, January 28, 1903, the 

 following papers were presented: 



Mr. S. F. Emmons, ' The Drainage of the 

 Valley of Mexico.' 



Mr. Emmons presented a sketch, illustrated 

 by lantern slides, of the various drainage sys- 

 tems of the valley of ]\Iexico, cuhuinating in 

 the elaborate and extensive works recently 

 completed at a cost of over 21J millions, that 



carry off not only the surplus waters in time 

 of flood, but also the sewage of the city of 

 Mexico. 



He also presented a sketch of the physiog- 

 raphy and geology of the valley, together with 

 some speculations as to the probable causes 

 of its change from a valley of the ordinary 

 type to the enclosed area without external 

 drainage of the present day, a change that 

 evidently occurred in very recent time, geo- 

 logically considered. 



Mr. Waldemar Lindgren, ' Notes on the 

 Geology of Molokai, Hawaiian Islands.' 



The island is entirely of volcanic origin, 

 and, like some others of the same group, is 

 made up of two old volcanoes separated by 

 a low gap. The western part of the island 

 is a volcanic mountain rising to an elevation 

 of about 1,200 feet. The eastern and most 

 interesting part forms a segment of a circle, 

 the north coast being the chord. The highest 

 peaks rise to nearly 5,000 feet above the sea. 

 While the southern slope is that of a fairly 

 regular volcanic cone and is scored by a great 

 number of ravines, the northern coast is 

 characterized by a great and extremely steep 

 escarpment attaining a height of over 3,000 

 feet above the sea. Five streams drain this 

 north slope and have eroded deep canyons 

 or alcoves. The escarpment is interpreted as 

 a great fault along which the northern half 

 of the volcanic cone has sunk down below 

 the sea. The peninsula of the leper settle- 

 ment at the foot of the escarpment is believed 

 to be a part of the thrown block. 



At the forks of the stream of Wailau great 

 boulders of coarse diabase were found, indi- 

 cating that in the upper drainage basin of 

 this stream there are extensive outcrops of 

 this rock, which has not heretofore been known 

 to occur in the Hawaiian Islands. 



W. C. Mendenhall, 



Secretary. 



the MONTANA ACADEMY OF SCIENCES, ARTS AND 

 LETTERS. 



The academy held its first meeting at Boze- 

 man at the same time as the meeting of the 

 State Teachers Association. Three sessions 

 were held, and ten papers were presented. 



