FREE BOOKS

Author's List




PREV.   NEXT  
|<   92   93   94   95   96   97   98   99   100   101   102   103   104   105   106   107   108   109   110   111   112   113   114   115   116  
117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   136   137   138   139   140   141   >>   >|  
nt he met with. For he sent all further communications to the Royal Society of London, which never had, and it is to be hoped never will have, anything of an academic constitution; and finally took himself off to Guadaloupe, and became lost to science altogether. Fifteen or sixteen years after the date of Peyssonel's suppressed paper, the Abbe Trembley published his wonderful researches upon the fresh-water _Hydra_. Bernard de Jussieu and Guettard followed them up by like inquiries upon the marine sea-anemones and corallines; Reaumur, convinced against his will of the entire justice of Peyssonel's views, adopted them, and made him a half-and-half apology in the preface to the next published volume of the "Memoires pour servir a l'Histoire des Insectes;" and, from this time forth, Peyssonel's doctrine that corals are the work of animal organisms has been part of the body of established scientific truth. Peyssonel, in the extract from his memoir already cited, compares the flower-like animal of the coral to a "poulpe," which is the French form of the name "polypus,"--"the many-footed,"--which the ancient naturalists gave to the soft-bodied cuttle-fishes, which, like the coral animal, have eight arms, or tentacles, disposed around a central mouth. Reaumur, admitting the analogy indicated by Peyssonel, gave the name of _polypes_, not only to the sea-anemone, the coral animal, and the fresh-water _Hydra_, but to what are now known as the _Polyzoa_, and he termed the skeleton which they fabricate a "_polypier_" or "polypidom." The progress of discovery, since Reaumur's time, has made us very completely acquainted with the structure and habits of all these polypes. We know that, among the sea-anemones and coral-forming animals, each polype has a mouth leading to a stomach, which is open at its inner end, and thus communicates freely with the general cavity of the body; that the tentacles placed round the mouth are hollow, and that they perform the part of arms in seizing and capturing prey. It is known that many of these creatures are capable of being multiplied by artificial division, the divided halves growing, after a time, into complete and separate animals; and that many are able to perform a very similar process naturally, in such a manner that one polype may, by repeated incomplete divisions, give rise to a sort of sheet, or turf, formed by innumerable connected, and yet independent, descendants. Or, what is still
PREV.   NEXT  
|<   92   93   94   95   96   97   98   99   100   101   102   103   104   105   106   107   108   109   110   111   112   113   114   115   116  
117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   136   137   138   139   140   141   >>   >|  



Top keywords:
Peyssonel
 

animal

 

Reaumur

 
anemones
 

published

 
polypes
 

polype

 

tentacles

 

perform

 

animals


habits

 
leading
 

forming

 

Polyzoa

 

anemone

 

admitting

 

analogy

 

termed

 

skeleton

 
stomach

completely

 

acquainted

 
discovery
 

progress

 

fabricate

 

polypier

 

polypidom

 
structure
 

repeated

 
incomplete

divisions

 

manner

 

separate

 

similar

 
process
 

naturally

 

independent

 
descendants
 

connected

 

innumerable


formed

 
complete
 

general

 

freely

 

cavity

 

hollow

 

communicates

 

seizing

 

capturing

 

division