SUMMARY OE CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 

 a. Embryologry.f 



Determination of Sex.J — 0. Schultze discusses this old problem in 

 a rigidly scientific manner ; and, after a survey of the data in regard to 

 plants (from Cryptogams upwards), and in regard to animals (from 

 Hydra to man), comes to the conclusion that the question of sex is 

 settled during the formative period of the ova. " The ova from which 

 we arise are formed at a time when our mother was still in the womb of 

 our grandmother, and are therefore without exception formed rather at 

 the cost of our grandmother than of our mother." His experiments on 

 influencing the sex of the second generation through the nutrition of 

 the grandmother (in mice) yielded no definite results. There seems no 

 reason to believe that the sex of the offspring can be affected after the 

 ovum is ripe. 



Embryology of Tumour s.§ — John Beard, in an exceedingly interest- 

 ing paper, expounds the following theory of tumours. A tumour is a 

 more or less reduced, more or less incompletely differentiated, sterile 

 Metazoan (animal) organism. It starts by the abnormal development 

 •of an aberrant or vagrant primary germ-cell, and growing under condi- 

 tions unfavourable for the complete and normal differentiation of all its 

 parts, it unfolds and develops those things for whose growth the nidus 

 is suitable, the rest degenerating, or remaining latent. In this way it 

 is seen that the physiological nidus accounts for the frequent " mimicry " 

 by tumours of their surroundings. As derived from primary germ-cells, 

 tumours are never parts of the organism in which they occur (contra 



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

 ■do not hold themselves responsible lor the views of the authors of the papers noted, 

 nor lor 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 published, and to 

 describe and illustrate Instruments, Apparatus, &c, which are either new or have 

 not been previously described in this country. 



t This sectiou includes not only papers relating to Embryology properly so called, 

 but also those dealing with Evolution, Development, Reproduction, and allied subjects. 



X SB. Phys.-Med. Ges. Wurzburg, No. 5 (ly02)j?p. 70-8. 



§ Anat. Anzeig. xxiii. (19U3) pp. 48b'-91. 



