920 



SCIENCE. 



[N. a Vol XII. No. 311. 



which will be consulted by students for gen- 

 erations to come. The other three great 

 collections are to be found at the Museum of 

 Comparative Zoology, at Cambridge, Mass. ; 

 the Academy of Natural Sciences, at Phila- 

 delphia, Pa.; and the TJ. S. National Mu- 

 seum, Washington, D. C. 



L. O. Howard. 



SCIENTIFIC BOOKS. 

 American Hydroids, Part I, The Plumularidse . 



By C. C. Nutting. WashiDgton, 1900. 



Published by the Smithsonian Institution. 



Pp. 285 ; pis. 34. 



We are accustomed to think of social life and 

 the division of labor as being especially char- 

 acteristic of highly organized beings, such as 

 ourselves among the vertebrates, and the ants 

 among the arthropods ; but as a matter of 

 fact socialism was invented and put into prac- 

 tice very early in the history of terrestrial life, 

 among creatures not so very far removed from 

 the most primitive types known to us. Pro- 

 fessor Nutting, in the splendid monograph now 

 under review, tells us (p. 46) that "Hydroids 

 ai'e exceedingly low in their organization and 

 exhibit in several respects the appearance of 

 loosely aggregated assemblages of cells which 

 are individually much like protozoa," and yet 

 he describes and figures the wonderfully differ- 

 entiated individuals or ' persons ' which make 

 up the beautiful and complicated feather-like 

 colonies of these animals. That there would 

 be some differentiation for reproductive ends we 

 might well expect, but the Plumularidse keep a 

 standing army of remarkably constituted indi- 

 viduals, supported by the common purse, and 

 fighting for the common weal. Listen here to 

 Professor Nutting : 



" As to the morphological significance of the 

 sarcostyles, all of the more recent authorities, 

 except Jickeli, regard them as degenerate in- 

 dividuals of the colony, or as ' fighting persons. ' 

 That they are individuals or ' persons ' is a 

 matter hardly admitting of doubt ; but it may 

 well be questioned whether they are degenerate 

 persons or not, and an argument might be con- 

 structed which would go to show that instead 



of being degenerate individuals they are in fact 

 very highly specialized persons. Specialization 

 is indicated when the structure has departed 

 from the original type in order to become 

 adapted to more definite and exclusive function. 

 It would seem that the sarcostyles have done 

 this very thing — departed from the original 

 type {Protohydra 9), and become morphologically 

 diflferentiated into individuals having the defi- 

 nite function of defense, in most cases, and of 

 prehension by means of adhesive cells in 

 others" (p. 28). 



All of which teaches us that, after all, living 

 protoplasm is the wonderful thing ; granting it, 

 the varied and complicated manifestations of 

 life may be said to follow naturally and inevi- 

 tably, their extent and variety dependent on 

 warmth and moisture, time and space, but their 

 essential nature what it was when life first ap- 

 peared upon the earth. 



These things may sound trite ; but while we 

 talk glibly of differentiation and evolution, we 

 do not always descend from the abstract to the 

 concrete, and realize the actual facts. Professor 

 Nutting's monograph should have this value 

 to the general zoologist and the teacher of sci- 

 ence, that it brings them as nearly into contact 

 with the things themselves and their way of 

 life as may be possible without a prolonged and 

 special study of the group. The study of types 

 may give us a certain knowledge of structure, 

 but without a real insight into life-histories, we 

 miss most of the fun, and may therefore be 

 thankful to be invited to partake of the prov- 

 ender so laboriously gathered for our benefit. 



In 1862, the elder Agassiz recognized only 

 three Plumularidse from the coasts of the United 

 States. To-day Professor Nutting makes us 

 acquainted with 121 American species, eight of 

 which, however, are not found north of the 

 Isthmus of Panama. Of the 121, no less than 

 52 have been first made known by Professor 

 Nutting himself. Most of the species come 

 from the West Indies, and it seems rather re- 

 markable that only ten are reported from the 

 whole Pacific coast of North America. Surely 

 more careful collecting off the coasts of South- 

 ern and Lower California should bring to light 

 a number of new forms. 



T. D. A. COCKEBELL. 



