152 



to the courses of these vessels, they are seen projecting in great num- 

 bers from the fractured edge ; and their vascularity may be readily 

 demonstrated with a power of 1020 linear, as they frequently contain 

 portions of an amber-coloured gelatinous matter, which induces a 

 slight increase in their diameters at those parts. One of the vessels 

 under these circumstances measured 1 T i 7 - g inch in diameter. 



In concluding the detail of my researches, I may be allowed to ob- 

 serve, that I have no doubt that many other interesting and beautiful 

 tissues will be found by future investigators of these highly organized 

 and elaborately constructed bodies, for I can assure my readers that I 

 have by no means exhausted the subject, but on the contrary, have 

 rather confined myself to pointing out the general laws displayed in 

 the organization of univalve and bivalve shells, than entered into a 

 detailed description of the numerous beautiful tissues that have passed 

 beneath my eye during the course of this series of observations ; and 

 the scientific conchologist, I am convinced, will find in the investiga- 

 tion of the organic tissues of shells, powerful assistance towards a na- 

 tural arrangement of genera, and a most efficient aid in determining 

 doubtful species. 



