SENSITIVE NERVE FIBRES. 



257 



The terminal nerve plexus of the sensitive nerve fibres is 

 Seen at the summit of the papilla, and it is remarkable that 

 the finest fibres of this plexus can be demonstrated with 

 greater distinctness in the papilla of the tongue of the hyla 

 or green-tree frog than in that of the common frog. The 

 papillae of these two closely-allied species, although exhibit- 

 ing the same general arrangement, present such well-marked 

 differences, that it would be possible, from the microscopical 

 characters of the papilla alone, to decide from which of the 

 two animals it had been taken. We are also able to learn 

 some important facts with reference to the connection 

 between the peripheral ramifications of nerves of special 

 sense, and those of motor nerves and the nerves of capillary 

 vessels which were first described by me. " Phil. Trans." 

 1864.* 



In these beautiful little organs we see a motor and sensi- 

 tive apparatus exquisitely adjusted and comprised within 

 very small compass. 



Anyone who will contemplate such an arrangement of 

 tissues as that which may be demonstrated in a specimen like 

 the one figured, will not rest satisfied with attributing it to 

 the " properties " of the elements entering into the chemical 

 composition of the substances out of which it has been 

 made. The " property " hypothesis accounts for absolutely 

 nothing. Its .advocates are unable to explain how one of 

 the tissues has grown into the form it ultimately takes, how 

 it acquired its structure, or how it came into relation with 

 adjacent textures. No wonder the disciples of " property ' 

 philosophy, pride themselves upon the interest they take in 



* See " Bioplasm," page 306. Plates XVI, XVIII, XIX, XX. 



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