90 BOOKS AND CURRENT LITERATURE 



or statement, lack of clearness clue to insufficient exposition of some 

 subjects mentioned or to vagueness of statement, occasional wrong 

 use of words, frequent poor English, all or nearly all due doubtless 

 merely to lack of care in the preparation of the book. A fuller treat- 

 ment of several of the types and of some of the general conceptions 

 would be advantageous. 



As inaccuracies note p. 70, conjugation a phenomenon universal 

 in animals and plants; p. 50, contractile vacuole of Amoeba heavier 

 than protoplasm; p. 47, acidity of liquid in gastric vacuoles of Amoeba 

 due to digestive ferments; p. 38, the scattered granules in bacteria are 

 chromatin; p. 80, minimum number of tentacles in Hydra 8; p. 91, no 

 specialization of furctional nervous fibres found in Protozoa (ef. Sharp 

 on Diplodinium) ; p. 103, cellulose a distinctive plant product (cf. p. 65) ; 

 p. 171, gill formula for Crawfish [this is of course different in Astacus 

 and Caihbarus]; p. 176, ears of lobster called auditory organs; p. 180, 

 a lobster detaches its muscles from the exoskeleton before shedding 

 the latter; p. 180, the lobster leaves the egg as a young lobster, reaching 

 the adult condition by growth; p. 194, scarlatina affects man only 

 [cows are also susceptible]; p. 201, Darwin treats natural selection as a 

 source of variations; p. 139, cilia absent on endodermal cells of typhlo- 

 sole of earthworm; p. 168, only digestible material enters the pyloric 

 stomach of lobster; p. 173, the duct of the green gland in the lobster 

 opens on the basal joint of the antennule; p. 161, "When organs have 

 the same ancestry, that is when they come from some common part 

 of an ancestral animal, they are said to be homologous" [this definition 

 of course does not include the serial homology in the appendages of 

 the lobster mentioned by Professor Calkins on the same page]. There 

 are numerous other instances. 



As statements of doubtful validity note p. 71, conjugation "a proc- 

 ess of protoplasmic reorganization followed by renewal or re-birth of 

 all vital activities including that of reproduction" [by the way, the 

 German custom of distinguishing between conjugation and copula- 

 tion is not followed by Professor Calkins]; p. 61, Paramecium is covered 

 by a lifeless pellicle; p. 32, processes of nutrition in yeast primitive; 

 p. 186, the scolex in the tape worm anterior [for what appears to be 

 a demonstration of the inaccuracy of this statement see Kofoid on 

 Gyrocotyle]; p. 187, proglottids of tape worm not metameres [cf. Ko- 

 foid on Gyrocotyle]; p. 231, "The history of the earth as written in modern 

 geology allows some hundred millions of years for modern types to 

 have evolved." [The planitesimal hypothesis greatly extends this 



