( 2.]^ ) 



not then, invclVigateil the formation of the cryftalliiic luiinour, I'o 

 accurately ii*^ I ought to have clone. 



I, therefore, firlt fat about exaniiniiio- tlial loelhcle or thin mem- 

 brane, wherein tlie cryftalline humour is inclofed, and by which it 

 is, as it were, Separated from the- otlicr luiinours, com)x)fino- the 

 llibftance of the ICye. I was then, well allured, tliat I faw this 

 membrane to be compofed of threads or iilaments, though after- 

 wards, notwithrtanding the greatefl attention that 1 could beflo\Y, 

 T could not diflinguifh Inch filaments. 



In this examination, I iometimes, but not often, obferved, tliatthe 

 fmall fibres compofing the filamentary fubftance of the external coat 

 of the cryftaUine humour, were united to the before mentioned mem- 

 brane ; whence I concluded, that this membrane w as ell'ential to the 

 cryltaUinc humour, in order to fmooth any inequahties that there 

 might be in tlie filaments of its external coat, and make its round 

 furface perfeSily even. ** 



I alfo confidered with myfelf, whether tliis membrane miglit 

 not be formed, for the jiurpofe, occafionally, by its rompreflion, 

 to alter the figure of the cryRalline humour; that is, to make its 

 rounding flia])e flatter at times, as the purpofcs of vifion might re- 

 quire ; and, if fo, this part of the Eye which has hitherto been called 

 the cryflalline humour, ought rather to be named, the cryflal- 

 line mufcle of the Eye : and yet, I cannot affirm with certainty, 

 that I have clearly feen tliis membrane to be compofed of filaments 

 intermixed one among another, though, I am well allured that it can- 

 not be formed in any other manner ; for, I have always found every 

 kind of thin membrane which I examined, to be of a filamentary or 

 fibrous make. With regard to this, now under confideration, I perceived, 

 when viewing it fideways, that it was compofed of a kind of flreaks 

 perfe6lly tranfparent, wliich I concluded to be, fome lymphatic 

 vefl'els, deftined for the nourilhment of the crvftalline liumour ; but 



