518 PHILOSOPHY OF ZOOLOGY. 



lar circumstances, those taken in the evening were alive at 

 noon on the following clay." 



The preparation of molluscous animals for exhibition in 

 a museum is attended with peculiar difficulty. The shells, 

 indeed, need only to be cleaned with a soft brush, and the 

 marine kinds to be steeped in fresh water, to extract all the 

 saline ingredients, and dried, when they are fit for the ca- 

 binet. The soft parts, however, can seldom be distended 

 by any substance, and dried. They are usually, therefore, 

 preserved in spirits of wine, where but too frequently they 

 appear a shapeless mass. The animal should be permitted 

 to die slowly, that the different parts may become relaxed, 

 otherwise the examination of the form of the body, at a fu- 

 ture period, becomes impracticable. A quantity of spirits 

 should be injected into the stomach, or other cavities of the 

 body, immediately after death, to prevent putrefaction, as 

 it frequently happens when the body is immersed in spirits, 

 without such precaution, that the viscera become unfit for 

 examination while the integuments have been preserved in 

 a sound state. 



n. 

 ANNULOSA. 



Brain surrounding the gullet and sending out a knot- 

 ted filament to the posterior extremity of the body. 



The longitudinal filament, which issues from the ventral 

 side of the nervous collar, is frequently double at its ori- 

 gin, and in some cases continues distinct throughout its 

 whole length. At each ring of the body it forms a ganglion, 

 and where the filament is double a union takes place of both. 

 From these ganglia nerves are sent to the neighbouring parts. 



Besides these conditions of the nervous system, there are 

 others connected with form and structure, which distin- 

 guishes the annulosc animals. In general their shape is 



