December 1, 1916] 



SCIENCE 



791 



he is going to use for experiments." The book 

 is written not for the elementary course in 

 invertebrate zoology, which is sometimes 

 offered as a part or the whole of a course in 

 general zoology, but for third and fourth year 

 undergraduates who are presumed to have 

 completed one or more courses in zoology. It 

 is the outcome of a course in which its author 

 attempts to give students, who desire more 

 zoology either from general or professional 

 interest, a foundational knowledge of inverte- 

 brate morphology, and very wisely he makes 

 no attempt to overload a large subject with 

 the many other interesting facts by which we 

 often think to re-clothe the dead bones — or in 

 this case perhaps one should say shells — of 

 morphology. The types included are as fol- 

 lows : Paramcecium, Grantia, Pennaria, Sertu- 

 laria, Tima, Gonionemus, Aurelia, Metridium, 

 Dendroccelum, Dicroccelium, Taenia, Ascaris, 

 Lumbricus, Nereis, Hirudo, Daphnia, Ho- 

 marus, Schistocerca, Agelena, Asterias, Ophio- 

 pholis, Pentacrinus, Arbacia, Thyone, Venus, 

 Limax, Loligo and Molgula. This list is com- 

 prehensive and probably represents as much 

 work as can be accomplished in the time 

 allotted to a course of this nature. Other 

 forms are promised, if the sales warrant a sub- 

 sequent edition. From the morphological 

 standpoint, this list is excellent and the re- 

 viewer would only suggest that the addition of 

 another Gastropod, preferably Helix, of notes 

 on the fresh-water mussel and of something 

 further upon the Entomostraca would be of 

 value. The presence of the fluke Dicroccelium 

 lanceatum in the list is an innovation which 

 will doubtless be welcome to American zool- 

 ogists, since it is so highly recommended; 

 though the reviewer has found a fluke from the 

 frog's lung, which he identifies as of the genus 

 Hcematolcechus, extremely satisfactory when 

 properly fixed and stained. The very com- 

 plete account of the spider Agelena nee via is 

 a valuable addition, as the arachnids have 

 often received scant attention, and reflects 

 the author's familiarity with this class of in- 

 vertebrates. In a paragraph entitled " Mate- 

 rial," which appears at the beginning of each 

 chapter, there is given a brief statement of 



the specimens and preparations needed for the 

 work outlined and of the author's methods of 

 technique. This information is valuable and 

 in a number of instances, such as the use of a 

 leaf in the killing of Dendroccelum lacteum 

 mentioned on page 55 and the method of pre- 

 paring Taenia, page 72, the reviewer notes 

 methods with which his experience in inverte- 

 brate zoology has not made him familiar. 



The distinctive feature of the volume is 

 the elimination of explanations and interroga- 

 tions from the Instructions and the inclusion 

 of all such matter in the Descriptive Part 

 which is a morphological monograph of the 

 form under discussion. The " instructions " 

 are reduced to such a degree that those for 

 the simpler forms and the sections of those for 

 more complex forms covering any one day's 

 work might almost be written out in full on 

 a blackboard of moderate size. There is no 

 attempt to put the student through his paces 

 or teach the method of induction through the 

 medium of the laboratory instructions. Such 

 brief directions demand rather more of the 

 instructor, but the plan is a good one with 

 students of the class for whom the book has 

 been written, as the reviewer knows from 

 having once or twice tried a similar scheme 

 in his own classes. In looking through these 

 instructions one gains an impression that 

 there are some drawings suggested which are 

 too difficult for any one without pronounced 

 artistic ability, as, for example, the figure of 

 the mouth parts of the lobster mentioned on 

 page 137, and there is perhaps a tendency to- 

 ward more isolated figures and fewer larger 

 and more comprehensive ones. This state- 

 ment, however, represents an impression which 

 might not be justified after the actual use of 

 the book in the laboratory. As a matter for 

 special commendation, the author of this re- 

 view notes the procedure outlined for the dis- 

 section of Molgula, which can be recommended 

 since it is essentially like a method which has 

 been developed in my own laboratory after 

 some disappointment at the failure of students 

 to master what seemed an easy matter. 



The figures are few in number, but in the 

 main good. Those of the Nematode on pages 



