May 2, 1919] 



SCIENCE 



423 



particular cases, but only to mention an im- 

 personal criterion for showing that the generic 

 determinations of bees in the lists cited were 

 erroneous. 



At first he takes the second of my alter- 

 natives and holds that the bees differ from all 

 of the other groups of insects, and even among 

 plants are only comparable with the Poales. 

 Then he changes about, makes the erroneous 

 assimiption that the bees and Lower Aculeata 

 were more completely represented in the local 

 list, and arrives at the mistaken conclusion 

 that such a condition would explain the dis- 

 crepancy between the averages of these insects 

 and the others. 



Stevens compares Andrena with Carex. 

 The so-called genus Andrena reminds one of 

 the time when all of the owls were referred 

 to Strix. It would not seem so large if the 

 sexes were not described as distinct species. 

 In a recent paper only 4.6 per cent, of the so- 

 called species were described from both sexes. 

 If one is so careless of his entomology and 

 diction as to say species when he means 

 sex, what is to keep him from saying subgenus 

 or quidnunc-group instead of genus? One 

 who ignores the fact that bees have two sexes 

 is not competent to distinguish any genera 

 except those based on characters common to 

 both sexes. If you should disregard the 

 secondary sexual characters and the habits of 

 the females, how well coiild you understand 

 the classification of the Hymenoptera in gen- 

 eral. 



Small divides Carex into two subgenera and 

 34 what-d'ye-call-'enis — named groups with 

 subfamily, family, ordinal and other endings. 

 One might like to know what categories the 

 organisms form, not how they are to be forced 

 to fit preconceived categories. The genus 

 seems to be regarded with superstitious rever- 

 ence when it contains 34 groups of the second 

 order. Even the analogy of the Poales is 

 against the bees. In the Fargo flora the 

 Poales stand 2.3 against a general average of 

 1.8, while in the Carlinville list the bees stand 

 6. 5 against an average of 1.7. 



Compared with the general average the bees 

 and Lower Aculeata show a great discrepancy 



in both lists without regard to their percent- 

 ages in the composition of them. The Coleop- 

 tera, respectively 33.7 and 10.6 per cent., ap- 

 proach the average in each list. Li the local 

 list the Coleoptera are quite fragmentai-y com- 

 pared with the Diptera, but tlie average is 

 about the same. The list of Rhopalocera, 

 which is as complete as that of the bees, shows 

 an average of 1.4 to the bees 6.5, while the 

 Heterocera, which are quite fragmentary, 

 average 1.2. The Bombyliidse, Conopidse, 

 SyrphidiB, Tachinidse and Muscidse, in which 

 the local list is quite complete, show 1.7 while 

 the other Diptera average 1.6. The 437 local 

 entomophilous flowers on which insect visitors 

 were taken average 1.6 while the 520 plants of 

 the Fargo flora average 1.8. 



Although Stevens argues against small 

 groups he says that he believes in the recog- 

 nition of them, but he doubts the necessity of 

 forcing them upon every one. The statement 

 that neglected groups will be subdivided about 

 like those which have been more thoroughly 

 studied hardly involves an attempt to force 

 small groups upon any one. You may say 

 that a river runs south without trying to force 

 the water on those who live down stream. 

 Charles Robertson 



Carlinville, Illinois 



geomorphology 



To THE Editor of Science: The letter from 

 Professor John L. Rich in your issue of Jan- 

 uary 11, 1918, escaped my notice at the time 

 and my attention was not drawn to it until 

 very recently. Hence this belated reply. 



I agree thoroughly with Professor Rich that 

 geomorphology has an interpretative geolog- 

 ical value, and I admit that, for the sake of 

 economy of space, it may be necessary some- 

 times to compress the geographical aspect of a 

 geomorphological description and its geolog- 

 ical interpretation into a single paper from 

 which the geographer and the geologist will 

 each attempt to pick out the points that in- 

 terest him. The introduction of certain geo- 

 logical dates into a paper with such a double 

 purpose is excusable, but it is the thin end of 

 a wedge which may lead to much obscurity. 



The artifice of placing geological names in 



