SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICROSCOPY, Etc.* 



ZOOLOGY. 

 VERTEBRATA. 



a. Embryology. t 



Treatise on Comparative and Experimental Embryology. $ — 

 0. Hertwig's great treatise continues to appear in instalments which 

 follow in rapid succession. Waldeyer deals in an almost monographic 

 manner with the sex-cells ; R. Hertwig treats of maturation, fertilisation, 

 and cleavage ; the editor discusses the theory of the germinal layers. 



Laboratory Text-Book of Embryology. § — Charles Sedgwick Minot 

 has adapted part of his great book on ' Human Embryology ' for use 

 in laboratory work. The aim of the new text-book is to utilise sections 

 of embryos as a basis for the morphological interpretation of adult 

 structure and in illustration of biological principles and pathological 

 processes. After a general chapter, the author discusses the early stages 

 in mammals, the human embryo till the fourth month, embryos of the 

 pig, embryos of the fowl, germinal layers and cleavage, the uterus and 

 the foetal appendages, and finally methods. 



Influence of Radium Rays on Tadpoles. || — G. Bohn finds that these 

 mysterious rays have a distinct but variable effect on the growth of the 

 tadpoles of frogs and toads, sometimes making it slower, sometimes 

 quickening it, sometimes destroying tissue, and sometimes inducing 

 monstrosity. He indicates that an effect produced during the tadpole 

 stage may remain as it were latent until the metamorphosis, when a 

 monstrosity suddenly results. 



Influence of Radium Rays on Ova.H— G. Bohn has made over forty 

 experiments with the ova of Strong ylocentrotus lividus, which were placed 



* 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 tbis 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 section includes not only papers relating to Embryology properly so called, 

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



J ' Handbuch der vergleichenden und experimentellen Entwickelungslehre der 

 Wirbeltiere,' Bd. i. Lief 9-13, 8vo, Jena, 1902-3. 



§ ' A Laboratory Text-Book of Embryology,' 8vo, Philadelphia, xvii. and 380 pp., 

 218 figs. 



|| Comptes Rendus, cxxxvi. (1903) pp. 1012-3. 1 Tom. cit., pp. 1085-6. 



