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Recent Literature. [October 



granted higher rank than a region of much less geographic extent com- 

 prising several times as many peculiar types. Hence the divisions here 

 recognized, and the rank assigned them, are based as far as possible upon 

 the relative numbers of distinctive types of mammals, birds, reptiles, and 

 plants they contain, vv^ith due reference to the steady multiplication of 

 species, genera, and higher groups from the poles toward the tropics." 



Dr. Merriam's studies of the life areas of North America have evidently 

 had a wide scope, and hare been prosecuted systematically and with great 

 thoroughness. His historical review of what has been done in this field 

 by previous workers, including a collation and tabulation of their results, 

 is alone a most useful and important contribution to the subject, as well 

 as an admirable preparation for further research. His experience in the 

 field also has given him the rare advantage of a personal knowledge of a 

 large part of the area he attempts to treat, and the opportunity of study- 

 ing on a grand scale the relation of cause and effect in the distribution of 

 animal and vegetable life. Besides possessing great familiarity with the 

 literature of the subject, he has at his command a mass of as yet un- 

 published details resulting from years of field work on the part of himself 

 and a large corps of collectors and assistants, systematically directed for 

 the express purpose of accumulating data bearing on the distribution of 

 life in North America. With such resources at his command one may 

 well hesitate to criticise his results, as unfolded in his several papers 

 above cited. Yet there are some points we had hoped to see settled that 

 are still left in abeyance, one being a consistent and well-grounded system 

 of nomenclature for the various life areas recognized. Hitherto each 

 writer has adopted such designations as seemed to him most convenient, 

 with little regard to preceding systems and terminology. As we hope 

 soon to treat this phase of the subject somewhat in detail in another 

 connection, we will merely add here that so far as Dr. Merriam's areas are 

 concerned, their boundaries, and in the main their assumed relationships, 

 ■we are in hearty accord with his results. As regards his classification and 

 nomenclature, we should prefer sundry changes, which, however, may not 

 be in conflict with Dr. Merriam's own views. Evidently he has not thus 

 far attempted to present a systematic scheme of terminology, his desig- 

 nations for different areas being descriptive and provisional rather than 

 the outgrowth of a broad scheme of classification, as regards their relative 

 rank and systematic terminology. — J. A. A. 



Suchetet on Hybridity in Birds. — The third part of M. Suchetet's work 

 on 'Hybridity among Birds in a Wild State'* treats of the Passeres, and 

 forms about 280 octavo pages. It shows a vast amount of painstaking 



* Les Oiseaux Hybrides | rencontres a I'etat sauvage | par | Andre Suchetet | — | 

 Troisieme Partie | Les Passereaux | — | Extrait des Memcires de la Societe Zoo- 

 logique de France | Tome V. page 253, annee 1892. ] — | Lille | Imprimerie typo- 

 graphique et lithographique le Bigot Frferes | 68, rue Nationale, et 9-11, rue Nicolas- 

 Leblanc | 1892. — Bvc, pp. 179-451 + i-v. 



