SUMMARY OF CURRENT RESEARCHES 



RELATING TO 



ZOOLOGY AND BOTANY 



(principally invertebrata and cryptogamia), 



MICEOSCOPY, Etc.* 



ZOOLOGY. 



VERTEBRATA. 



a. Embryology, t 



Inheritance of Coat Colour in Horses. J — C C. Hurst has inferred 

 from an examination of Weatherby's " General Stud Book of Race 

 Horses" that in modern thoroughbred horses chestnut colour is a 

 Mendelian recessive to bay and brown, which are dominant characters. 

 The consideration of other colours being excluded, bays and browns are 

 of two kinds : — (a) Those that when mated with chestnuts will give 

 no chestnut offspring ; (b) Those that when mated with chestnuts will 

 give on an average, half their offspring chestnuts and the remainder 

 bays and browns. Similarly, the recessive chestnuts, variously extracted 

 from the dominant bays and browns, breed true, as a rule, when mated 

 together, without reversion to their bay or brown ancestors. Nine 

 exceptions were found in 1104 cases, and these may be due to errors in 

 the records. 



The late Professor W. F. R. Weldon§ studying the same subject 

 reached the following conclusions : — 



1. No simple Mendelian view of the relation between chestnut, bay, 

 and brown, regarding chestnut as a simple recessive, can be maintained. 



2. The chance of getting a chestnut foal from a chestnut mare is not 

 constant for sires of any colour whatever, and there is no indication that 

 sires of any colour can be sorted into groups such that those in each 

 group will give chestnut foals in a Mendelian proportion when mated 

 with chestnut mares. 



* 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. 



J Proc. Roy. Soc, Series B, lxxvii., No. B 519, pp. 388-94. 



§ Tom. cit., pp. 394-8. 



