REVIEWS 695 



After a brief introduction and discussion of the nomenclature, we have a 

 general review of the literature, starting with Galen. This is followed by- 

 three long sections dealing with the comparative morphology of the pineal 

 complex, the comparative embryology of the complex, and the comparative 

 anatomy and histology of the same. These sections go into the most import- 

 ant literature in more detail, summarise the previous findings under the various 

 species of animals, and give an account of the author's own researches. This 

 is a valuable piece of work, for it enables one to pass under review the results 

 of numerous authors scattered in different periodicals. Here, however, a 

 criticism is called for. In our opinion Dendy's work on Sphenodon is not 

 sufficiently emphasised, and, what is less explicable, there is no reference to 

 this author's work on Geotria australis, one of the Cyclostomes. This, however, 

 is one of the latest and best memoirs on that subject, and, concerning as it does 

 one of the lowest groups of Vertebrates, is of importance in considering the 

 comparative aspect of the question. These descriptive portions are illustrated 

 by a number of figures and plates. Many of the text-figures are excellent, 

 others err somewhat on the side of being too schematic — tins, however, is not 

 the fault of the authors, since they are reproduced from other papers. In 

 certain cases the reproductions of photomicrographs are good, but in others 

 they are poor. It is a pity that the more important of them, at any rate, were 

 not reproduced by collotype or similar process upon a better grade of paper, 

 since half-tone prints on ordinary paper, we feel sure, do not do justice to 

 either the original photographs or the preparations. 



The concluding section is in the form of a discussion which, since it is 

 preceded by such a mass of readily available evidence, is very valuable. It is 

 preferable, as the authors point out, to consider the relationships of the pineal 

 area or complex as a whole, and not to deal with isolated parts, such as the 

 pineal gland and the parietal eye. The position is maintained that this 

 apparatus cannot be considered as a vestigial one, and two of the most interest- 

 ing conclusions are : ' . . . the epiphyseal complex of vertebrates possesses 

 a pluripotentiality whose fundamental inherent tendency is in the interest of 

 glandular differentiation, but in a few instances, as in Cyclostomes, Amphibia, 

 and in primitive Reptiles, the pineal organ may become further differentiated 

 in the interest of a highly specialised sensory mechanism, winch has or has 

 had visual function;" and again, "The phylogenetic significance of the 

 parietal eye in Vertebrates as the homologue of the median eye of Inverte- 

 brates should be accepted with much reservation." 



On the whole this is a thorough and valuable contribution to our knowledge 

 of these structures in the brain and the problems they present, and although 

 it does not claim to have answered satisfactorily all the questions it raised, 

 has undoubtedly cleared the ground, and should serve as a useful stimulus to 

 further research. C. H. O'D. 



A Geographical Bibliography of British Ornithology, from the Earliest Times 

 to the end of 1918. By W. H. Mullens, M.A., LL.M., F.L.S., 

 M.B.O.U. ; H. Kirke Swann, F.Z.S. ; and Rev. F. C. R. Jourdatn, 

 M.A., M.B.O.U. Part I. [In six bi-monthly parts.] (London : 

 Witherby & Co., 1919. Price per part, 6s. net.) 

 Messrs. Mullens and Swann have already contributed so much first-class 

 and invaluable work to bibliographical literature, that the present contribu- 

 tion, in conjunction with the Rev. Jourdain, will be heartily welcomed by all 

 British ornithologists. 



This work forms a supplement to their recent Bibliography of British 

 Ornithology (1917). This was, however, purely biographical, while the present 

 volume is geographical, i.e. each section is devoted to a county. Practically 

 all the works referred to in the first volume, under the alphabetically arranged 

 names of authors, again appear, but this time under the name of the county 



