aSo Sthntific News, Accounts of Soeh, i^fi'. 



Zoology. — On the monoculous Flea, — By the vulgar name of water-flea is known a fmall 

 cruftaceous animal, very abundant in ilagnant waters, which has fometimes given rife to 

 the ftory of fhowers of blood, becaufe in the fpring its ova with which it is filled, give it a 

 red colour, and the waters containing many of thefe animals do then in fa£i appear as if 

 they contained blood. The moft fkilful naturalifts, Swammerdam, De Geer, SchoefFer, 

 and Otto-Frederick Muller, have fucceflively ftudied this animal, but nature is inex- 

 hauftible in her fmalleft produftions. Citizen Jurine, aflbciate of the Inftitute of Geneva, 

 has difcovered in this infeft a number of curious circumftances which had efcaped thofc 

 learned men. He has defcribed at large its internal and external organization, its fexual 

 intcrcourfe, &c. The moft fingular fa£t he has difcovered is, that the female, which has 

 received the male, tranfmits the influence to its female defcendants, fo that they all pro- 

 duce eggs, without recourfe to the male to the fixth generation, after which their young 

 perilh in the hatching. Another fpecies has carried this influence of a fingle copulation to 

 the fifteenth generation. It is known that fleas have afforded fimilar obfervations to 

 Bennet. Thefe generations without conjundtion are lefs abundant, and fucceed each other 

 lefs rapidly than thofe in which the communication of the male has taken place. 



Botany. — Defcription of the new, or fcarcely known plants in the garden of Citizen Cels, 

 by C. Ventenat. Of the magnificent work here defcribed, four livraifons have already 

 appeared, each containing ten plants. 



Hijlory of the Oaks of America. — It Is fomewhat fingular, that the fpecies of the oak 

 which are fo few in Europe, ftiould be fo diverfified under the fame latitude in America. 

 Ci Michaux has given a hiftory of thefe numerous fpecies, which is the more interefting, 

 as it is probable that fome of them may be of much utility when tranfplanted into Europe. 



Anatomy.-^On the Symphifis of the Pubis. — Citizen Tenon, who has long been occupied 

 en this part of the anatomy of the human fubjeft, has afcertained that the os pubis does 

 rot feparate but in fuch pulvis' as have a double cartilage, in which cafe the ligaments only 

 arc lengthened, and that this ftru€lure is the leaft frequent. 



Technology. — New method of waOiing linen. For the account of this procefs of Chaptal, 

 vide our laft Number, page 233. 



Paper making. — C. Seguin, who has been five years employed on the art of manufac- 

 turing paper, has made feveral ufeful difcoveries to expedite the progrefs. The manufac- 

 ture of paper from ftraw difcovered fo long ago in Germany, and lately carried into eiFett 

 in this country, is among the improvements of C. Seguin. But he has not communicated 

 any of his methods to the Inftitute. 



