4 DR. J. F. GBMMILL ON [May 12, 



2nd series, 1870, pp. 2049-2052), has given several instancesof 

 the abnormal extension of red in this species, some forms of which 

 appear to be fairly common. 



" Some attention has been directed of late to a variety of the 

 Ruff which has the head and neck white or nearly so, even in 

 winter plumage when the oi'naniental plumes are absent. The 

 specimen exhibited died recently in the Zoological Society's 

 Gardens, having made, at any rate this year, little progress in 

 putting out a ruff. Specimens of the variety kept in the Calcutta 

 Zoological Garden, however, have produced the nuptial plumage, 

 which was as white as the same parts had been in winter. There 

 were two of these birds, which differed in their back-feathering 

 as much as other Euffs, one being rufous-mottled, while the 

 other was grizzled. The variation is evidently albinistic, as it 

 may, though very rarely, affect the Reeve as well as the Ruff. 

 There is such a specimen in the Indian Museum, procured half-a- 

 century ago by Blyth. I myself have obtained several specimens 

 of the form in the Calcutta Bazaar, which, without exception, 

 were adults, as shown by the colour of their feet ; so that the 

 variation in question would seem to supervene late in the life of 

 the individual possessing it. The white-headed birds kept alive 

 did not seem at all deficient in vigour, and no doubt under 

 especially favourable circumstances this very beautiful variety 

 might become quite common. It has, however, the obvious 

 disadvantage of being very conspicuous, which may, perhaps, 

 account for its restiiction to adult individuals." 



Mr. F. E. Beddard, F.R.S., exhibited and made remarks upon 

 some preserved and injected brains of Mammalia which had been 

 prepared from specimens formerly living in the Society's Gardens. 



The following papers were read : — 



1. A Contribution to the Study of Double Monstrosities in 

 Fishes. By James F. Gemmill, M.A., M.D., Lecturer 

 in Embryology, Glasgow University *. 



[Received May 12, 1903.] 



(Plates I.-IY. t ) 



This paper contains an account of the anatomy of a set of 

 double monster Trout embryos, studied from serial sections and 

 illustrated by reconstruction drawings. For purposes of com- 

 parison, a similar but shorter account of the anatomy of normal 



* Communicated by P. G. Parsons, F.Z.S 

 t For explanation of the Plates, see p. 21. 



