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derives its nerves from the lenticular ganglion. They pierce 

 the sclerotic not far from the optic nerve, and gaining the 

 inner surface of this coat they run forwards between it and 

 the choroid till they reach the ciliary muscle, on the outer 

 surface of which they break up and re-combine in the well- 

 known beautiful plexus, a large portion of which is, however, 

 destined for the innervation of the iris. From this coarse 

 plexus bundles of nerve-fibres dip into the muscle, in which 

 they form a finer net, from which single fibres of extreme 

 tenuity are traceable for long distances amongst the muscular 

 bundles, but I have not yet discovered the actual nature of 

 their ultimate connection with the muscular fibre. In my last 

 course of lectures, I adverted to the occurrence of ganglion 

 cells in the plexus. They first became known to me by the 

 beautiful preparations of Schweigger, and are not the coarser 

 gangliform swellings recognisable under slight enlargement 

 described by Dr. R. Lee, jun. The arteries of the ciliary 

 muscle are drawn from the circulus arteriosus major iridis, 

 which distributes many recurrent twigs to it. There are not 

 unfrequently ofi"sets of the arterioles which this arterial circle 

 sends to the ciliary processes. The venous blood escapes in 

 two directions, posteriorly though veinlets wdiich join those of 

 the ciliary 2:)rocess and lead to the vena vorticosa, and in front 

 through veinlets which empty their contents into the circulus 

 venosus in Schlemm's canal. 



The Lens and Intra-ocular Muscles of Mammals, Birds, 

 and Reptiles, — Having gained this insight into the apparatus 

 of accommodation as it exists in the human eye, it will 

 not be uninteresting to trace some of its modifications in 

 other members of the vertebrate series. 



I should like to take this opportunity of expressing my 

 great obligations to the Zoological ; Society for the un- 

 rivalled facilities they have afforded me by placing at my 

 disposal the eyes of a very large number of the animals which 

 have died in their gardens. Their kindness has placed me 

 under obligations I can never repay. 



In all mammalia, monodelphous as well as didelphous, as 

 far as my observations extend, — and through the liberality of 

 the Zoological Society of London, to Avhich I am more in- 

 debted than words can express, I have enjoyed unrivalled 

 opportunities of examining the eyes of a very large number of 

 animals dying in their gardens, — the lens and ciliary muscle 

 do not differ in any essential point from those of man. In 

 all other mammalia the lens is more spherical than in man. 

 In most the central planes are three, as in the human foetus ; 

 in a few (cetaceans and some rodents) there is but one plane. 



