ENTOMOLOGICAL CABINET. 



if one be selected which has the intestinal canal free, 

 or nearly free, from food, as the success of the ob- 

 servation will greatly depend upon this circumstance. 

 In fixing the larva for observation, which of course 

 must be in water, great care must be taken not to 

 compress the body, as although the central circula- 

 tion may be seen proceeding with considerable vig- 

 our, that through the lateral vessels, and those of 

 the tail, legs, and antennae, will either be much 

 impeded or entirely stopped. Having fixed the in- 

 sect, with the above precautions, and with its back 

 towards you, a truly beautiful and astonishing sight 

 presents itself. The blood, abounding in flattened 

 oat-shaped particles, will be seen circulating in every 

 part of the body, not in a continuous stream, but at 

 regular periods, agreeing in its motion with the pul- 

 sations of the great dorsal vessel." 



