137 



through two wires, such wires repel each other, because their op- 

 posite sides are in similar magnetic states. 



A Communication of a singular Fact in Natural History. By the Right 

 Honourable the Earl of Morton, F.R.S. In a Letter addressed to 

 the President. Read November 23, 1820. [Phil. Trans. 1821, 

 p. 20.] 



Being desirous of domesticating the Quagga in this country, his 

 Lordship endeavoured to procure some individuals of that species, 

 but being disappointed in obtaining a female, an attempt was made 

 to breed from the male and an Arabian chestnut mare ; the result 

 was a female hybrid, now five years old, and showing her mixed 

 origin both in form and colour. 



The Arabian mare has since been bred from, by a black Arabian 

 horse, and the produce, namely, a two year old filly and a year old 

 colt, though in most respects fine specimens of the Arabian breed, are 

 marked with certain stripes and fines belonging exclusively to the 

 Quagga : the manes are especially unlike those of the Arabian breed. 

 It is a striking fact, observes his Lordship, that so many features not 

 belonging to the dam, should in two successive instances be trans- 

 ferred by her to the progeny of a sire who has them not. 



Particulars of a Fact, nearly similar to that related by Lord Morton, 

 communicated to the President', in <i Letter from Daniel Giles, Esq. 

 Read November 23, 1820. [Phil. Trans. 1821,;?. 23.] 



In the litter of a black and white sow, by a boar of the wild breed, 

 the chestnut colour of the boar strongly prevailed ; a second litter 

 from the same mother, by a boar of a very different breed, retained 

 many peculiarities of the wild breed ; and even in a third litter the 

 chestnut colour was to a certain extent evident. 



The Croonian Lecture. Microscopical Observations on the following 

 Subjects. On the Brain and Nerves ; showing that the Materials 

 of ivhicti they are composed exist in the Blood. On the Discovery 

 of Valves in the Branches of the Vas breve, lying between the Villous 

 and Muscular Coats of the Stomach. On the Structure of the Spleen. 

 By Sir Everard Home, Bart. V.P.R.S. Read December 7, 1820. 

 [Phil. Trans. 1821,;?. 25.] 



By a microscopic examination of the retina and optic nerve, Mr. 

 Bauer found them to consist of globules of -rsW to -nro-o- of an inch 

 diameter, united by a transparent viscid and coagulable gelatinous 

 fluid : the brain also, according to the same observer, consists of the 

 same globules, united by the viscid jelly, and forming a fibrous ar- 

 rangement. 



After describing the peculiarities in texture of the different parts 

 of the brain, Sir Everard adverts to the circumstance of lymphatics 



