August 8, 1884. 



SCIENCE. 



Ill 



single purpose of the study of man, it seems 

 impossible that it should long remain without 

 a much larger support from friends of Ameri- 

 can archeology and ethnology. We hope that 

 the trustees will be encouraged in their efforts 

 b} r a large increase to the subscriptions for 

 American explorations, in addition to those 

 mentioned in our notes. 



European naturalists regard the attention 

 paid in this country to economic entomology, 

 and the aid that has been given it by various 

 states and by the general government, as one 

 sign of 'a practical people.' With all the 

 specialization in instruction in the foreign uni- 

 versities, we are not aware that there is more 

 than one which supports a professorship of 

 entomology. This is Oxford, where the ven- 

 erable Professor Westwood honors the Hope 

 foundation. In this country, Harvard and 

 Cornell each have their full professorship of 

 this science ; and to the latter a summer school, 

 haying special reference to agricultural ento- 

 mology, has now been attached. This seems 

 more appropriate than many of the summer 

 schools now so much in vogue, inasmuch as 

 the objects of study are at this season in the 

 height of their investigations into the power 

 of crops to sustain insect-life. To further the 

 interests of the school, the trustees of Cornell 

 university have relieved Professor Comstock 

 of his duties during the winter semester ; and 

 an unusually good opportunity is thus afforded 

 to teachers, as well as others, to familiarize 

 themselves with the principles of this branch 

 of economic science. 



was the first American to advocate this relation of 

 propylite and andesite, which he did in a paper pub- 

 lished before that of Rosenbusch. In Wads worth's 

 paper it was remarked, that his microscopic studies 

 of the Washoe and other western propylites, collected 

 by Richthofen and the Fortieth parallel exploration, 

 had led him to conclude of these typical propyl itic 

 rocks, that "the propylites are all altered andesites, 

 with which species their chemical composition agrees; 

 and that the diagnostic distinctions that Professor Zir- 

 kel has placed between the andesites and propylites did 

 not hold good, even in the specimens that he described, 

 as would have been readily seen, had he given com- 

 plete descriptions instead of the very imperfect and 

 often inaccurate ones that have been published. 

 The distinction between these rocks is simply in the 

 degree of alteration; and they pass directly into each 

 other." 1 



Now, although Messrs. George F. Becker and Arnold 

 Hague are fully known to have knowledge of this 

 publication, they not only ignore completely the 

 priority of Wadsworth, but also use language which 

 would cause any reader not conversant with the 

 subject to believe that Becker was the first American 

 to oppose the species propylite. 



In connection with a professed history of the dis- 

 cussion of the Washoe rocks, Becker states, " Baron 

 von Richthofen based the independence of the new 

 rock propylite largely upon the occurrences in the 

 Washoe district. Later investigators in the same 

 field, without exception, have adopted his views. 

 Professor Zirkel's characterizations of the microscop- 

 ical peculiarities of propylite were also founded 

 chiefly on the Washoe occurrence. Though at the 

 beginning of the present investigation [April, 1S80] I 

 was fully persuaded of the independence of propy- 

 lite, I subsequently found reason to doubt it : but to 

 prove a negative is notoriously difficult, and the great 

 authority of my predecessors made the task still more 

 onerous." 2 



Mr. Hague writes, "Recently Mr. George F. Becker, 

 in his work on the Washoe district, made a thorough 

 investigation of the so-called propylite, and as a result 

 denied the independence of the rock-species. . . . We 

 quite agree with him, so far as the non-existence of 

 propylite as a distinct rock-species in the Great Basin 

 is concerned." 3 



Any one who is conversant with the storm Wads- 

 worth's before-mentioned paper of 1879 excited will 

 have no difficulty in understanding why it is that 

 these and some other geologists, who are now stand- 

 ing on almost if not quite identical ground with him, 

 should proceed in such a manner.*- 



M. E. Wadsworth. 



Museum of comparative zoology, 

 Cambridge, Mass., July 21. 



LETTERS TO THE EDITOR. 



*** Correspondents are requested to be as brief as possible. 

 The writer's name is in allcases required as proof of good faith. 



Some United States geologists, and the propy- 

 lite question. 



Your reviewer of the recent publications of the 

 U. S. geological survey incorrectly states that Dr. 

 Becker does not give Rosenbusch credit for his prior 

 advocacy of the view that propylite is a modification 

 of andesite {Science, iv. p. 67), for Becker does so 

 on p. 90 of his ' Geology of the Comstock lode; ' but 

 your reviewer ought to have stated that Wadsworth 



Swarming insects. 



The editor was slightly unfortunate in his sugges- 

 tion appended as a note to the letter of Mr. Abbott 

 (Science. No. 77). I have just returned from Lake- 

 side, Ottawa county, O., where the phenomenon 

 spoken of by Mr. Abbott was witnessed almost every 

 day for more than two weeks. The pulsating swarms 

 were, beyond question, the ' Canada soldiers," a spe- 

 cies of Ephemera. 



During the first ten days of the present month 



1 Bull. mus. comp. zool., 1S79, v. 2S5. 



2 Geology of the Comstock lode, 1SS2, p. 33. 



3 Amer.joitr?i. sc, 18S4 (3), xxvii. 454. 



* See, further, Proceedings of the Boston societv of natural 

 history, 1SS3, xxii. 412-432 : and 1881, xxi. 243-274. 



