114- 



nel, so as to become adequate to the discharge of the water. The 

 peculiarities of the rise and fall of the tides at adjacent places, is re- 

 ferred by the author principally to the accumulation that takes place 

 in these basins. That the tides do not meet at Dungeness in a line 

 across the Channel, is further proved by the absence of that violent 

 concussion of water which in such a case would ensue; the fact being, 

 that the formation of the coast by gradually altering the course of 

 the tide between the South Foreland and buoy of the Nore, from 

 E.N.E. to W.N.W. within the stream of the Goodwin Sands, oc- 

 casions a gentle blending of the waters, so that there is only a strong 

 eddy about the Kentish Knock, and a foamy rippling where they 

 meet and proceed onwards together. 



On the Ova of the different Tribes of Opossum and Ornithorhynchus. 

 By Sir Everard Home, Bart. V.P.R.S. Read March 25, 1819. 

 [Phil. Trans. 1819, p. 234.] 



With his previously acquired knowledge respecting the formation 

 of the ova of quadrupeds in Corpora lutea, Sir Everard proceeds to 

 inquire into that of the Opossum tribe, the ova of which are not 

 formed in the same manner, but make two distinct gradations be- 

 tween the quadruped and Ornithorhynchus paradoxus, which last 

 approaches so near to the bird, as to complete the link of grada- 

 tion between the quadruped and bird in their mode of generation. 

 Sir Everard first describes the formation of the ova in the Kan- 

 garoo, which, when expelled from the Corpus luteum, receive a yolk 

 in the Fallopian tube, and afterwards the albumen in the uterus. 

 The foetus, when expelled from the uterus into the marsupium, at- 

 taches itself to the nipple, as described in the 85th and 100th volume 

 of the Philosophical Transactions. In the Kola and Wombat, and 

 great and small Opossum, instead of Corpora lutea there are yolk 

 bags imbedded in the substance of the ovarium ; and there are two 

 uteri, with a Fallopian tube to each, the ovum in each uterus being 

 separately impregnated in its own cavity. 



The mode of formation of the ova in the Ornithorhynchi, forms the 

 intermediate link between the Opossum anil bird. The yolk bags 

 are imbedded in the ovaria ; and instead of a regular uterus, each 

 Fallopian tube swells out into a cavity, in which the ova are impreg- 

 nated. 



The Results of Observations made at the Observatory of Trinity Col- 

 lege, Dublin, for determining the Obliquity of the Ecliptic, and the 

 Maximum of the Aberration of Light. By the Rev. J. Brinkley, 

 D.D. F.R.S. and M.R.I. A. and Andrews Professor of Astronomy 

 in the University of Dublin. Read April 1, 1819. [Phil. Trans. 

 1819, p. 241.] 



The obliquity of the ecliptic, as deduced from the early observa- 

 tions by the Greenwich quadrant, compared with the present ob- 



