94 NOTES AND COMMENTS [febkttaey 



the members of each group as sub-species of one species, which he 

 regards as the archetype. 



It is obvious that a satisfactory application of this method 

 is possible only in cases where the geographical distribution has 

 been approximately worked out, and, like any other method, its 

 operation must not be pushed too far. It should at any rate prove 

 of service to those who are working at floras of limited areas, 

 and to such especially we would commend a careful perusal of Dr. 

 Wettstein's essav. 



Irrelevant Generalities. 



The biological inquirer of to-day is like the fisherman of the old 

 story who tapped a flask on the sea-shore and let loose a cloudy 

 genie ; he explores a concrete object, it may be the sperm-cells 

 of a snail or the wings of an insect, and forthwith there emerges 

 upon him and upon us a looming cloud of " allgemeine Betrachtungen," 

 the genie of general biology, who will in nowise return to his 

 flask. So far, doubtless, it is well that every research should 

 have a wide horizon ; but anyone who has read, say, the papers 

 of the last five years relating to spermatogenesis, will surely agree 

 with Mr. Bernhard Eawitz {Arch. f. mikr. Anat. 1898, liii. p. 20), 

 that the generalising tendency is often as irrelevant as it is tedious. 

 It is not necessary that everyone should point out every time 

 how the often small item of new fact which has been securely 

 established by his research bears upon the problems of cell-division, 

 fertilisation, heredity, and the like, " ohne dass dabei ein erkleklicher 

 wissenschaftlicher Gewinn abfiel." " Very many authors," says 

 Eawitz, and he has our sympathetic concurrence, " seem to me 

 like a geographer who describes the province of Brandenburg and 

 hangs on to that a discussion of the whole physical geography 

 of the northern hemisphere." We know of irrelevant detail, like 

 that of the venerable geologist who could not discuss graphite 

 without bringing in the life-history of the Faber family ; but 

 there are irrelevant generalities as well, and it is hard to say 

 which are most exasperating. 



The Chinch Bug. 



In volume viii. of Natural Science (p. 376) reference was made 

 to Mr. F. M. Webster's studies on the distribution of the Chinch Bug 

 (JBlissus leucopterus, Say) in North America. An exhaustive monograph 

 on the insect by the same naturalist has just been issued as Bulletin 

 15 (N.S.) of the Entomological Division of the U.S. Department 

 of Agriculture. Though intended primarily for the farmer's use — 



