374- 



Ann. Par. 

 The first seven observations were made~| The comparison 



near opposition, the next eight near > of these gave a ;/ 



conjunction J result of 2' 18 



The next set were seven at opposition, 1 . . 



and eight at conjunction / & vm % 3 



The last set eight at opposition, and eight 1 , 



at conjunction / & ave 2 



3)7-56 



So that by the result of 47 observations, the result is 2"'52 ; and 

 Dr. Brinkley adds, that from the confidence which he has now ac- 

 quired in his instrument, he has no doubt that the annual parallax 

 exceeds 2". 



This letter also contains some remarks upon refraction with the 

 co-latitude of the Dublin Observatory, as deduced by means of dif- 

 ferent formulae. From these it appears, that the agreement by De- 

 lambre's tables is nearer than by Dr. Bradley's own formula; but that 

 Dr. Bradley's formula, by means of a slight correction, gives a table 

 preferable to that of Delambre. 



Dr. Bradley's is 



56-9 x tag. (zen. dist. - 3 Refr.) 



Dr. Brinkley's corrected formula 



56-9 x tang. (zen. dist. - 3'2 Refr.) x htbarom - 50 



29-6 450+6 



On the Mode of breeding of the Ovo-viviparous Shark, and on the Aera- 

 tion of the foetal Blood in different Classes of Animals. By Everard 

 Home, Esq. F.R.S. Read June 7, 1810. [Phil. Trans. 1810, 

 /7.205.] 



With a view to understanding more fully the structure of the 

 Squalus maximus, of which Mr. Home has lately published an ac- 

 count, he has examined with attention that of the Squalus acanthius, 

 which appears to resemble it closely in its internal structure, and has 

 the advantage of being very easily obtained upon the Sussex coast, 

 where it is very common. 



After describing minutely the external organs of generation in 

 both male and female, the author traces the progress of the ovaria 

 from the time that the yolks are no larger than peas, till they become 

 as large as walnuts, when they pass into the oviduct. The number 

 of yolks differs in different fish ; and even in the same fish Mr. H. 

 has seen five yolks in one ovarium and only two in the other. The 

 oviducts then enlarge, and become exceedingly extended, and divided 

 by contraction of its coats into three cavities, the last of which is ten 

 inches in length, and is that in which the eggs are retained till the 

 young fishes are formed, and capable of taking care of themselves. 



