Mr Rooke on remarkable Aciitations of the Sea. 141 



two laminae, before it has itself attained the diameter of half 

 a line, a fifth membrane haA'ing disappeared by liquefaction 

 within the ovum. 



The size of the minute ovum in the Fallopian tube and ute- 

 rus affords no criterion of the degree of its development ; nor 

 do any two parts of the minute OAOim, in their development, 

 necessarily keep pace with one another. 



The proportion of ova met with in these researches, which 

 seemed to be aborted, has amounted to nearly one in eight. 

 Sometimes two yelk-balls exist in the same ovum. With 

 slight pressure, the ovum, originally globular, becomes ellip- 

 •tical. Its tendency to assume the latter form exists especial- 

 ly in the chorion, and seems to be in proportion to its size. 



The author has discovered, that when the germinal vesicle 

 is first seen it is closely invested by an extremely delicate 

 membrane. This membrane subsequently expanding is that 

 in which the yelk is formed. He has traced the chorion from 

 stage to stage up to the period when it becomes villous, and 

 shews that it is not, as he formerly supposed, the thick trans- 

 parent membrane itself of the ovarian ovum, but a thin enve- 

 lope closely investing that membrane, and not appreciable as 

 a distinct structure until the ovmn has been crushed. When 

 the chorion first admits of demonstration as a distinct struc- 

 ture the ovum consists of tlu'ee membranes, a state which the 

 author has seen in an o^alm no farther advanced than about 

 an inch into the Fallopian tube. The chorion subsequently 

 thickens and imbibes a quantity of fluid presenting a gelati- 

 nous appearance. 



Notice of remarkable Agitations of the Sea at the Sandwich 

 Islands, on the 1th November 1837. By T. Chas. Byde 

 RooKE, F. R. C. S. 

 On the evening and night of the 7th November, a most re- 

 markable commotion of the sea was witnessed at Hanolulu, 

 in many respects similar to that witnessed at these islands in 

 May 1819. One inch and a-half of rain had fallen during 

 the previous twenty-four hours ; the wind was fresh from the 

 N, E., squally at intervals. The atmosphere was clear and 



