150 



SCIENCE 



[N. S. Vol. XXXIII. No. 839 



against which especially the recent investiga- 

 tions of W. Manchot might be cited. 



The fine reproduction of 100 plates of 

 beautiful microphotographs of hemoglobin 

 crystals of various species of animals is es- 

 pecially noteworthy. 



Leo Loeb 



A Monograph of the Culicidce or Mosquitoes. 



Volume 5. By Fred V. Theobald. British 



Museum (Natural History). London. 



1910. Pp. xvi-l-646. 261 text figures, 6 



plates. 



The author has assembled in this volume 

 descriptions of many recently erected genera 

 and species, characterized thirteen genera and 

 eighty species as new, supplied keys for the 

 separation of the genera and a very large pro- 

 portion of the described species and, in addi- 

 tion, gives observations or references to 

 practically all other genera and species. This 

 latter makes the fifth volume practicalls'' a 

 systematic index to the preceding four vol- 

 umes and will greatly facilitate future studies 

 in this group. 



The modified classification proposed by 

 Lutz and outlined in volume four has been 

 closely followed. We regret to note that the 

 tables for the recognition of the genera are 

 based largely upon scale structure, a method 

 of separation which has found comparatively 

 slight favor in America, though we can not 

 ignore the author's statement, especially in 

 view of his wide experience with these insects 

 from all parts of the world, that separation in 

 this manner is comparatively easy, as evi- 

 denced by the number of correctly named col- 

 lections received at the British Museum. The 

 monograph, as a whole, is weak from a struc- 

 tural and biological standpoint, ' and necessa- 

 rily so in many instances, especially in the 

 case of forms received from distant countries 

 where methods of collection and preservation 

 are far from ideal. The study of the imago 

 must, as a rule, precede biological investiga- 

 tions, and it is therefore not surprising that 

 the immature stages have received compara- 

 tively little attention in this work. We 

 sympathize strongly with the author in his 



declining to recognize genera and species 

 based solely upon larval characters, despite 

 the fact that such procedure is not sanctioned 

 by the International Code of Zoological 

 Nomenclature. It is true that good characters 

 are found in the larvse of this group, and that 

 in some instances species are more readily 

 separated in the larval than in the adult form. 

 Nevertheless, our classification of the family 

 is based upon the imago, and confusion is 

 bound to result from the employment of a 

 double standard; though technically allowable, 

 it is in this group questionable procedure. 



There are important problems in synonymy 

 which should be settled in the near future for 

 the purpose of avoiding confusion if for no 

 other reason. The author declines to accept 

 the broad delimitation of Aedes, recently pro- 

 posed in this country, and, as a consequence, 

 the nomenclature used by a number of Amer- 

 ican workers differs widely from that em- 

 ployed in the volume under consideration. 

 Personally, without having made special 

 study of the problems involved, we question 

 the wisdom of attempting to unite under one 

 name such diversified forms. On the other 

 hand, a number of generic names have been 

 allowed to stand as valid in this work which 

 will probably fall as synonyms because of the 

 absence of satisfactory characters. These and 

 similar questions can be settled only by an 

 exhaustive comparative study of the char- 

 acters presented by the immature stages as 

 well as those of the adult. The key to the 

 solution of many of these problems will be 

 found in the unrivaled collections from all 

 parts of the world, now assembled in the Brit- 

 ish Museum of Natural History. 



The diversity and size of this group is indi- 

 cated by the eight subfamilies recognized 

 (excluding the Corethridse), comprising some 

 146 genera and 899 species, a large majority 

 of these being valid. The world owes Pro- 

 fessor Theobald a debt of gratitude for as- 

 sembling, carefully describing and arranging 

 this immense amount of material, among 

 which are included some of the most danger- 

 ous insect enemies of man. Prior to this 

 study, our knowledge of the Culicidfe was 



