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SCIENCE 



[X. S. Vol. XXV. No. G32 



branching of such thallophytes as Diciyota 

 dichotoma and such liverworts as Biccia fiui- 

 tans. It occurs, apparently, wherever a 

 branching organ extends itself unimpeded in 

 one plane. Its veide-spread independent oc- 

 currence is evidence that it is the result of 

 developmental dynamics, and there can be no 

 doubt it is primitive. 



The author thus ' having traced the de- 

 velopment of these systems of veins ' (p. 73) 

 proceeds with full assurance to the application 

 of his theory. He has no difficulty at all in 

 identifying his marginal vein in the catch on 

 the inner edge of the elytron of Coleoptera 

 (p. Y5). It is safe to say that no other vena- 

 tion theorist has ever ridden his hobby so far 

 as this. His primary vein, ' invariably found 

 in functional wings ' (p. 63), is absent from 

 at least one of the wings shown on p. 100. 

 With respect to the Odonata-anisoptera, in 

 discussing the triangle, he says : " It does not, 

 nor does the wing of any of the Anisoptera, 

 show any transition between a triangular and 

 a quadrilateral cell." The ignorance of our 

 own fauna and its literature shown by this 

 statement is not more surprising than the 

 readiness with which he ignores the illustra- 

 tive genera that are mentioned in the legend 

 to the figure he is criticizing. But these and 

 other misstatements concerning the Odonata 

 will not mislead the students of that order. 

 Having ignored tracheation and also the like- 

 ness in venation between Plecoptera and Or- 

 thoptera, he is able to give a different inter- 

 pretation of the two orders. But the great 

 superiority of his theory appears in the treat- 

 ment of the venation of the fossil Homo- 

 thetidffi (p. 102), Embiidse (p. 106) and Phy- 

 sopoda (p. 126). Even the last named, for 

 whose puzzle no one has hitherto ventured a 

 solution, is instantly resolved by the applica- 

 tion of the ' rational theory ' ! It is wonder- 

 ful. The only trouble with it is that it is too 

 easy. When in doubt about a vein call it 

 what it most resembles in the hypothetical 

 diagram. " Class as an independent vein any- 

 thing that anywhere exhibits structures char- 

 acteristic of independent veins" (p. 69). 

 Throw away the usual safeguards against mis- 

 interpretation of parallelisms: they are all 



superseded by the application of a mechanical 

 theory I 



And when we reach the end of it, we 

 find that its goal is another system of vein 

 nomenclature! This is formally compared, 

 vein by vein, with four' (out of the dozens) of 

 systems proposed in the past. It is hard to 

 see why the author, since he identifies all of 

 these in detail including the generally recog- 

 nized branches, should have thought to ad- 

 vance entomology by a new batch of names 

 for them. It is not easy to understand why, 

 if the new terms marginal and primary, etc., 

 may be used in an elastic sense, as provided on 

 p. 145, the old terms casta, radius, etc., might 

 not, if it were necessary, be so used, equally 

 well. 



Other peculiarities of this work are the 

 ignoring the literature of the subject for 

 nearly the last decade and of important 

 papers on the mechanics of insect wings, much 

 older : the misspelling of the names of authors 

 cited, Aaron, de Selys Longchamps and Mc- 

 Lachlan (the last in two ways), and evident 

 misstatement of facts, such as this : " An 

 increase in the size of a wing usually re- 

 sults in an increase in the number of veins " 

 (p. 65). There is no justification in mor- 

 phological experience for the statement that 

 " increase in a wing area would do just the 

 same things that a decrease would undo " 

 (p. 80) and that the " direct effect of environ- 

 ment would be suiEcient " to differentiate two 

 groups (p. 9) is surely assuming something. 

 The statement of p. 145 that other workers 

 have not recognized that the same names 

 should be applied only to homologous organs, 

 is a fine bit of assumption. There is a mys- 

 ticism about the account of the genesis of the 

 venation that is somewhat unusual in a scien- 

 tific paper : page Y9 is full of it ; and the state- 

 ment that the primary vein was developed to 

 be the dominant vein (p. 144) reminds one of 

 the statement of that other narrative of 



" Those attributed to Comatoek are the names 

 selected by Eedtenbacher as most available. 

 They were in his day and are now the ones in 

 most common use, and to their adoption no 

 serious objection has ever been offered. 



