559 



SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICEOSCOPY, Etc.* 



ZOOLOGY. 



VEBTEBBATA. 



a. Embryology, f 



Development of Limbs in Ox and Pig4 — N. Suschkina-Popowa 

 has studied the development of the extremities in Bos and Sus, and has 

 compared the ontogeny with what can be inferred from the pakeonto- 

 logical series in regard to the phylogeny. Certain events take place in 

 ontogeny in the same order as in phylogeny. Thus there may be noted 

 the disappearance of the first digit, the coalescence of certain carpal and 

 tarsal elements, and the coalescence of the median metapodials — first in 

 the hind limb and then in the fore limb. Historically, the first digit of 

 tbe hind leg disappeared earlier than the first digit in the fore leg, and 

 it is relatively late of appearing in ontogeny. 



In some respects the ontogenetic picture differs from the phylo- 

 genetic. In the history of Artiodactyls the trapezium remains for a 

 long time persistent ; sometimes, even in recent Cervicornia, it remains 

 after the fusion of trapezoid and magnum. But in the ontogeny of Bos 

 this element does not appear. The fibula becomes interrupted in the 

 ontogeny of Bos after the fusion of the ulna with the radius. But it is 

 otherwise in the phylogenetic history. 



The reduction of the first two and the lateral toes is condensed in 

 the individual development. Historically, the first toe disappears first ; 

 the lateral toes retain their original thickness and length after the com- 

 plete disappearance of the first toe ; later on they also begin to dwindle. 

 But in the individual development of Bos the first toe and the lateral 



* The Society are not intended to be denoted by the editorial " we," and they 

 do not hold themselves responsible for the views of the authors of the papers 

 noted, nor for any claim to novelty or otherwise made by them. The object of 

 this part of the Journal is to present a summary of the papers as actually pub- 

 lished, and to describe and illustrate Instruments, Apparatus, etc., which are 

 either new or have not been previously described in this country. 



t This section includes not only papers relating to Embryology properly so- 

 called, but also those dealing with Evolution, Development, Reproduction, and 

 allied subjects. 



% Bull. Soc. Imp. Nat. Moscow, xxviii. (1915) pp. 209-78 (2 pis.). 



