412 HISTORY OF ZOOPIIYTOLOGY. 



unknown and neglected, until the remarkable experiments of 

 Abraham Trembley, in 1741, on the reproductive powers of 

 the fresh-water polypes,* and more especially his discovery of 

 the Plumatella, itself a plant-like animal production, while 

 they extorted the wonder and admiration of every one enga- 

 ged in the study of natural science, were the means of recall- 

 ing to the recollection of Reaumur the views of Peyssonnel ; 

 and he now became forward in promoting such inquiries as 

 seemed likely to confirm and extend them. He himself 

 appears to have repeated the experiments of Trembley, and 

 had an opportunity of observing the habits of the Plumatella; 

 and, as he remarks, since the number of species of animals 

 which are covered by the waters of the sea is much greater 

 than that of the fresh waterSj so it seemed natural to presume 

 that not only would polypes be found in the ocean, but in 

 greater numbers and variety than in ponds, rivers or rivulets. 

 To ascertain the validity of this conjecture, and to settle if 

 possible the discrepancy between the observations of Marsigli 

 and Peyssonnel, his friends Bernard de Jussieu and Guettard-|- 

 proceeded, in the autumn of 1741 and 1742, to different parts 

 of the coasts of France with the view of examining their 

 zoophytical productions ; and both were soon satisfied of the 

 truth of the animal theory. Bernard de Jussieu in particular 

 shewed that it was equally applicable to many zoophytes 

 which Peyssonnel had not examined, and whose animality 

 had not yet been suspected, viz. the flexible and delicate 

 Sertularise, the Flustra, and the Alcyonium or Lobularia, the 

 last of which seems to have excited much astonishment by 

 the protrusion of its thousands of polypes of a size large 

 enough to be seen and examined at ease with the naked eye.| 

 The memoir which Jussieu presented to the Academy of 

 Sciences in Paris is short, but characterized by great distinct- 

 ness and precision in the detail of his observations, and illus- 



* In the Phil. Trans, for 1742, the reader will find a full account of this dis- 

 covery. 



t Lamouroux speaks highly of the labours of this naturalist, whose attention seems 

 to have been chiefly directed to fossil polypidoms and to sponges. Corall. Flex. 

 Introd. p. xvii. See also Hall. Bib. Bot. ii. 341. 



X Exaraen de quelques productions marines qui ont et6 mises au nombre des 

 Plantes, et qui sont I'ouvrage d'une sorte d'lnsectes de mer. Par M. Bernard de 

 Jussieu. 14th Nov. 1742. Published in 1745.— See Hall. Bib. Bot. ii. 201. 



