Scientific Intelligence. — Zoology. ISST 



body, and then a semi-transverse cut to remove the upper quar- 

 ter, not only will the three remaining quarters speedily repro- 

 duce a new fourth, but also the separate fourth will form to it- 

 self three new quarters. Indeed a planaria has been cut into as 

 many as ten pieces, and each piece has become an entire and 

 perfect animal. In fact, this mode of propagation, which phy- 

 siologists artificially institute, seems to be frequently resorted to 

 by the animal itself. The Planaria felina has been seen to 

 throw ofl* pieces of its body to form new animals ; and these are 

 not diseased, but healthy parts; and not only parts of its tail, 

 but often offsets from its sides, &c. Indeed, the Planaria felina 

 and P. arethnsa have been never known to lay eggs ; whilst the 

 torva, lactea, &c. lay them in abundance, both the original ani- 

 mals and those artificially produced. It would seem that those 

 species which inhabit springs and running waters propagate on- 

 ly by division ; but those which dwell in ponds and ditches, 

 where the water is occasionally exhausted, are oviparous, as 

 well as viviparous. The above facts are physiologically curious, 

 as they shew a still closer affinity than had previously been sup- 

 posed to exi<^t between the propagation of plants and animals 

 by cuttings as well as seeds, for they have shewn that this mode 

 of propagation can be carried to an almost equal extent in the 

 one as in the other, — an extent to which the experiments of 

 Trembley and others on polypi, star-fish, &c. did not reach. 

 -^Medical Gazette, Feb. 1832. 



8. Presence of Entozoa in the Eyes of AnimaU.—YiiXheT- 

 to, worms have been seldom, and in small numbers, found in 

 the eyes of animals. M. Nordman has, however, met with them 

 in all the eyes of fishes, reptiles, and birds. In the summer 

 of 1829, he met with an immense number in most fishes. It is 

 particularly in the vitreous humour, near thecompanula Halleri, 

 and even in the crystalline lens, tliat he has observed them in 

 groups of from 60 to 100 individuals. They are generally of 

 a new genus of the Nematodes ; he has also met with two new 

 distomas, contained, as he say, in hydatids ; and finally, very 

 rarely a species of capularis<— Z>wM7i Medical Journal. 



9. On the Formation of Pearls. — Dr Baer of Koenigsberg 

 rejects the old hypothesis, lately revived by Sir Everard Home, 



