656 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Epithelium of Human Epididymis.*— R. Ikeda finds that both the 

 ciliated and non-ciliated cells of the coni vasculosi are secretory ; there 

 is here no*bther special glandular organ . The ciliated cells arise from the 

 non-ciliated ; and at the same time the central corpuscles (diplosomes) 

 as Benda has described, increase and grow. There is evidence that the 

 diplosomes serve for regeneration of the cilia. The transition from vasa 

 efferentia to vas epididymis is gradual. The cylinder cells of the vas 

 epididymis are not genuine ciliated cells, but secreting cells ; their hair- 

 like tufts serve to conduct the secretion, and in this function it appears 

 the contents of the nucleus share. The diplosome of the duct epithe- 

 lium lies immediately under the cell surface, or rather deeper in the 

 cell-body ; between it and the tuft there is no connection. The central 

 corpuscle is to be sought exclusively in this diplosome. 



Non-Nucleated Blood Corpuscles in Vertebrates.t — C. S. Engel 

 has found non-nucleated red blood corpuscles in the unhatched chick 

 from the fifth to the eighteenth day, and in frog larvae till the dis- 

 appearance of the tail. In many cases in the frog tRe position formerly 

 occupied by the nucleus can be distinctly seen in the corpuscle. In 

 both bird and frog a nucleated portion can be seen connected by a 

 protoplasmic thread with the non-nucleated portion. The non-nucleated 

 blood cell may arise by karyolysis, or by the division of the embryonic 

 cell into a nucleated and a non-nucleated portion. 



Erythrocytes of Siredon pisciformis.J — A. E. v. Smirnow, by 

 using Kopsch's prolonged osmium method, has demonstrated Meves's 

 " superficial network " and transverse threads. 



Chromosomes of Lepidosiren paradoxal — J. A. Murray has studied 

 these in cells of all tissues of embryos. He finds that the number is in 

 all probability thirty-six ; they form a group of variously sized elements ; 

 possibly the various sizes occur in a fixed number. The arrangement of 

 the chromosomes in the daughter plate (and in the amphiaster) depends 

 upon their size : the smaller lie nearer to the spindle axis than the 

 larger. 



c. General. 



Vitalism.|| — Hans Driesch gives a history of vitalistic theories from 

 Aristotle to the " neo-vitalists " of to-day, and an outline of his own 

 doctrine. The historical part of the book has three main parts, dealing 

 (1) with the old vitalism from Harvey and Stahl to Haller, Blunien- 

 bach, and Burdach, and thence to Johannes Muller and Liebig, Kant 

 and Schopenhauer ; (2) with the criticism of the old vitalism and the 

 materialistic reaction, with special attention to Lotze and Claude 

 Bernard ; (3) with the new vitalism from von Hartmann onwards. 



The constructive part of the book begins with a discussion of the 

 harmony and " regulation " which are criteria of adaptive phenomena in 

 organisms. It proceeds to demonstrate on a basis of facts the autonomy 



* Anat. Anzeig., xxix. (1906) pp. 1-14, 76-81 (1 pi. and 8 figs.) 



t Tom. cit., pp. 144-7. \ Tom. cit., pp. 236-41 (5 figs.). 



§ Tom. cit., pp. 203-8 (6 figs.). 



|| Der Vitalismus als Geschichte uud als Lehre, Leipzig, 1905, 246 pp. 



