08 



transparent, is placed over the animalcules:, which 

 are flattened by the preure of tin: ^ I on 15 



an the observation lasts. The second, requiring still 

 more dexterity, takes place by separating the larger 

 species, with a very sharp and cutting needle, but it 

 require* an extremely good eye and patience. 



Perseverance, so necessary in fill -orts of re- 

 searches, if indispensable in microscopic obsefT*! 

 which must, be often repeated rind varied; but Hint 



trouble is amply rewarded, and the pleasure felt by 

 the investigator, who discovc so beau- 



tiful, SO hurpri/ing and unexpected, is beyond de- 

 scription. 



FORM AND ORGANS. 



According to the organisation of tfcftU animalcules, 

 we can dixidi- them info tuo nbdi\iiled into 



.six families, vi/. the \r/r.if:u(f/<', Hie dovmtiriu, 1'lnti- 

 Htru , l''r<i(jil<iriac, , Cloxl.crui. and Arl/n'oifif/c.. The 

 three first families: have a brittle tegument, the three 

 others a flexible one; but, in order to n-coani/c 

 exactlv the form of the.se creature: - it i 

 to describe each of the organs which compost- them. 



The external tegument (t^idcrmi^) of UK- .- ,,m- 

 malcules i of tv\o species. It is ;,. >ilic-(,u . t ; 

 patent and vitreous shell, called ruirmtv (lojic.i). 



