178 ANIMALCULA OF INFUSIONS. t, 



but an elongated facculus covered with tuber- 

 cles : Many aquatic animals are fimply of a mem- 

 ^ branaceous or vafcular texture. Many marine 

 zoophytes are only a kind of jelly. The organi- 

 zation of thefe animals has not the fmalleft rela- 

 tion to that of man ; plants themfelves may be 

 faid to refemble him more, becaufe we find fap 

 veflels, utricles, and tracheae in them ( i ). 



The 



(i) Every fmall animal was formerly called an infed, 

 and is fo ftill, by incorred writers. The fub-divifions of 

 animated nature muft become more numerous, in propor- 

 tion as fcience advances, and peculiar diftindive properties 

 are difcovered. A great family has been feparated from 

 proper Entomology, and called cnijlacea : but another, 

 much more immenfe, has been removed farther under the 

 •name Vemiei ; and additional changes are made by every 

 new writer. But it will be long before they are univer- 

 fally obferved, particularly in imperfed infeds and worms. 



It was generally believed, that none of the animals de- 

 nominated infeds had any brain, and very few ventured 

 to difpute the fad ; and after they did fo, the reverfe was 

 pertinacioufly maintained. Haller lays it .down as a general 

 rule, that all animals, having a head and eyes, muft alfo 

 have a brain and fpinal marrow : he thinks, neidier eyes 

 without a brain, nor a brain without eyes, exift in any 

 animal ; likewife, that all thofe with a brain and fpinal 

 marrow muft alfo have nerves, Phyftologia., Tom. 4. p. 2. 

 J550 Fabiicius fays, inleds have only the rudiments of a 



brain. 



