544 



Iu the case of the perihelia no other two semicircles give a greater 

 disproportion between the numbers. The semicircle 355 to 175 

 contains 37 of the nodes, the opposite one 13. 



But in addition to this development of my original plan regarding 

 the heliocentric longitudes of the perihelia and nodes, Mr. Graham 

 has found a remarkable coincidence between the foregoing numbers 

 and the periods of the discovery of the small planets. It appears 

 that 28 have been detected between the vernal and autumnal equi- 

 noxes, and only 15 in the other half-year. 



He states that this circumstance, which at a first glance might 

 seem to throw some light upon the facts, proves, after a moment's 

 consideration, the exact opposite to what might have been expected, 

 at least in its bearing on the perihelia, for 



180 to 360. to 100. 



Longitudes of Aphelia 29 14 



Longitudes of descending Nodes . . 28 15 



Point of Ecliptic in opposition at 



28 . 1 5 



date of discovery 



opposition at i 



"If, then," Mr. Graham adds, "there be any connexion between 

 these results, it is not easy to imagine why discoveries should be more 

 frequent near the descending node ; and it is quite contradictory that 

 there should be a greater facility of finding the planets in the more 

 remote parts of their orbits." Upon these facts I abstain from 

 making any comment, excepting that the present data tend to 

 strengthen the conviction that some physical cause, as yet unapplied 

 to these phenomena, may be in operation. Appended to this paper 

 are two diagrams, bringing before the eye more clearly than numbers, 

 the heliocentric places of the perihelia and nodes which are the sub- 

 jects of this notice. 



XVIII. " On the Development of Carcinus Mamas." By 

 SPENCE BATE, Esq., F.L.S. Communicated by Sir W. 

 SNOW HARRIS, F.R.S. Received May 1st 1857. 



(Abstract.) 

 The author, after noticing the history of the subject, and the 



