COMPARATIVE ANATOMY. 



IV. Neuroplera / four reticulated wings. 



1. Libellula, dragon-fly. 



2. Ephemera, &c. 



V. Hymenoptera ; generally possessing a 

 sting. 



1. Vespa, wasp, hornet. 



2. Aspis, bee. 



3. Formica, ant. 



4. Termes, white ant. 



5. Ichneumon, &c. 



VI. Diptera , two wings. 



1. (Estrus, gad-fly. 



2. Musca, common flies. 



3. Culex, gnat, mosquito. 



4. Hippobosca, horse-leech, &c. 



VII. Jlptera ; no wings. 



1. Podura, springtail. 



2. Pediculus, louse. 



3. Pulex, flea, chigger. 



4. Acarus, tick, mite. 



5. Aranea, spider. 



6. Scorpio, scorpion, &c. 



The vermes may be divided into 

 two orders; the intestinal, which inha- 

 bit the bodies of other animals ; and the 

 external. 



The former are not of such a compli- 

 cated organization as the latter ; so that 

 they are sometimes arranged among the 

 zoophytes. The external worms have a 

 nervous chord possessing ganglia, an 

 elongated body composed of rings, and 

 having no distinct head ; there are no 

 members ; circulating vessels, but no 

 heart ; no nerves have been discovered 

 in the intestinal worms. 



Order \. Intestini. 



1. Gordius, guinea-worm. 



2. Ascaris, thread-worm, 



worm. 



3. Tricocephalus. 



4. Fasciola, fluke. 



5. Txnia, tape-worm. 



6. Hydatis, hydatid. 



II. Externi. 



1. Aphrodite, sea-mouse. 



2. Sipunculus. 



3. Hirudo, leech. \ 



4. Nereis. 



round- 



5. Nais. 



6. Planaria. 



7. Lumbricus, earth-worm, &c. 



The Zoophytes have neither brain nor 

 nerves; no heart, nor, perhaps, blood-ves- 

 sels ; no articulated members. 



Order. I. Echinodermata ,- covered by a 

 hard and tough coriaceous skin. 



1 Echinus, sea hedge-hog. 

 2. Asterias, star fish, &c. 



IT. Soft or Gelatinous Zoophytes. 



1. Medusa, sea-blubber, sea net- 



tles. 



2. Actinia, sea-anemone. 



3. Hydra, fresh water polype. 



III. Infusoria, the animalcules of infu- 

 sions. 



1. Vorticella, wheel-animal. 



2. Brachionus. 



3. Vibrio, eel of vinegar. 



4. Volvox. 



5. Monas. 



IV. Inhabitants of corals, corallines, 

 sponges, &c. 



COMPARATIVE OSTEOLOGY. 



It has been asserted, that the bones in 

 some instances have not their ordinary 

 white colour. Thus the amedabad finch, 

 (fringilla amandava,) and the golden 

 pheasant, have been said to possess 

 yellow bones ; but this is not true. In the 

 garpike (esox belone) the bones are 

 green ; and in some varieties of the com- 

 mon fowl in the East Indies they are 

 black ; but this colour is said by Mr. Hun- 

 ter to reside in the periosteum. 



The opinion of Aristotle, that the bones 

 of the lion had no marrow, is totally un- 

 founded. 



The bones of the cranium are much 

 more completely ossified at the time of 

 birth, in the mammalia, than in man. In 

 the former the fontanells are hardly dis- 

 cernible. When we compare the pelvis, 

 and the whole mechanism of parturition 

 in the woman, with those of the female 

 quadruped, the cause of this difference 

 appears; we then discover, why the yield- 

 ing and over lapping of the large 

 bone of the cranium, which is chiefly 

 effected by the fontanells, is only requir- 



VOL. III. 



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