NOVEMBEK 12, 1909] 



SCIENCE 



6S3 



their general organization, with special treat- 

 ment of the segmentation, appendages, body 

 cavity and nephridia, alimentary, reproductive 

 and respiratory organs. The nervous system 

 is entirely omitted, also the musculature and 

 moulting phenomena, and the treatment of 

 the nephridia is rather superficial and not il- 

 lustrated by figures. The second chapter, on 

 the Branchiopoda, is by far the best on any 

 section of the Crustacea, contains many new 

 figures and unpublished observations on the 

 habits, and terminates with useful keys for 

 the identification of all genera of the Phyl- 

 lopoda and all British genera of the Cladocera. 

 The remaining chapters contain few new il- 

 lustrations. Chapter HI. deals with the 

 Copepoda, TV. with the Cirripedia and Ostra- 

 coda (to the latter is devoted only a little over 

 two pages), and Chapters V. and VI. with the 

 Malacostraca. The parasite Sacculina is well 

 treated, with interesting new observations. 

 Parasitic castration is considered, also partial 

 and temporary hermaphroditism (these terms 

 are rather objectionable) and normal her- 

 maphroditism. Phosphorescent organs are in- 

 terestingly described, but in connection with 

 the compound eyes no mention is made of the 

 work of G. H. Parker. The remainder of the 

 treatment is mainly taxonomic. Chapter VII. 

 deals with the geographical distribution of the 

 group, including the relations of fresh-water 

 and marine faunae, and the author accepts 

 the view of Ortmann, for which there is now 

 80 much evidence, of an original land connec- 

 tion between the continents of the southern 

 hemisphere. While the section on the Crus- 

 tacea is clearly written, many important 

 morphological phenomena are either omitted 

 or mentioned most briefly. 



The Trilobita are very well treated by 

 Henry Woods in 31 pages, about two thirds of 

 the account being devoted to their structure. 



Professor Shipley gives in the brief Chapter 

 IX. an introduction to the Arachnida, essen- 

 tially in agreement with the views of Lan- 

 kester. He subdivides the Arachnida into the 

 Delobranchiata (though there is no good rea- 

 son why this should replace the better known 

 Merostomata), and Embolobranchiata ; the 



former includes the Xiphosura and EurjT^ter- 

 ida, the latter the Scorpionidea, Pedipalpi, 

 Aranete, Palpgradia, Solifugse, Chernetida?, 

 Podogona, Phalangidea and Aearina. He 

 places the Tardigrada and Pentastomida as 

 " appendices " to the Arachnida. 



The Xiphosura are also treated by Shipley, 

 in 21 pages. He follows Lankester in making 

 the eye segment the first, the rostral the 

 second and the cheliceral the third. There is 

 no good description of the eyes or discussion 

 of their homologies, and no figures of them, 

 so that the treatment is decidedly scant, espe- 

 cially in comparison with that given by 

 Korschelt and Heider in their " Lehrbuch." 



The Eurypterida are well described by 

 Henry Woods in 12 pages, with good figures 

 from the best restorations. 



Cecil Warburton has written the accounts 

 of the remaining arachnidan groups, the 

 Embolobranchiata, and his treatment is a 

 useful contribution, for this is the fullest text- 

 book account yet given of these groups. The 

 best part is the biological and taxonomic, for 

 not much attention is given to the internal 

 anatomy and almost none to the embryology. 

 All the taxonomic families are characterized, 

 though not in the form of analytic keys. 



To the Scorpionidea are devoted 12 pages, 

 with the internal anatomy given most briefly; 

 to the Pedipalpi, 5 pages; to the Palpigradi, 2 

 pages; to the Solifugse, 7 pages; to the Cher- 

 netidse, 9 pages, with a list of all British 

 species; to the Podogora (Ricinulei), 2 pages; 

 to the Phalangida, 15 pages, a good treatment. 

 fii the greater number of text-books the pre- 

 ceding groups, with the exception of the 

 scorpions and solifugids, receive only the 

 barest mention. The large group of the 

 Aearina is treated in 20 pages, too briefly. 



The fullest attention is given, however, to 

 the Aranese or spiders, more than a hundred 

 pages being occupied with this group. There 

 is a good description of the external anatomy 

 and the stridulating organs. But the internal 

 anatomy is too briefly treated, the colulus and 

 various salivary glands are entirely omitted, 

 also the entapophyses, the endosternal struct- 

 ures (a most serious omission) and the 



