Miscellaneous. 463 



9. The epidermis of the seed is formed in the Leguminosa only of 

 one integument, which, however, always separates into several layers. 



10. No endopleura tumida exists in the Leguminosce ; what has been 

 considered as such is albumen, and in fact endosperm. 



The authors have also discovered that the ovules of the genus Lu- 

 pinus are only provided with a simple integument, while those of the 

 other Leguminosce always possess a double one. 



ON THE STRUCTURE OF THE SCALES OF FISH AND REPTILES. 



M. Mandl, in a memoir presented to the French Academy, states 

 that the scales are composed of a superior and of an inferior layer. 

 The upper layer is composed, a. of longitudinal canals, proceeding in 

 the form of longitudinal lines, from a point which is not always the 

 centre of the scale ; b. oi cellular lines, i. e. of lines in which he 

 thought he perceived the margins of successive layers of increase, but 

 which, according to his observations, were nothing more than lines 

 produced by the union or fusion of cells ; c. of yellow corpuscles ana- 

 logous to the corpuscles of bones, and of cartilages containing salts 

 like them ; <?. of a focus occupied by interrupted cellular lines, by 

 imperfect cells and corpuscles, &c. : the focus appears to be the first 

 rudiment of the scale ; e. of the teeth of the scale, which exist only 

 on the terminal margin in the Acanthopterygians and are wanting in 

 the Malacopterygians. 



The inferior layer is composed of fibrous lamellae, of which the 

 outer ones are the longest. The elements of the fibrous layers, 

 which in hard scales frequently shine through the superior layer, 

 may be isolated by rupture. 



The author concludes from his observations that the scales cannot 

 be regarded as simple products of secretion, but that a true organi- 

 zation must be admitted in them. M. Mandl also considers with 

 M. Agassiz that the scales may serve as characters in classification. 

 — Comptes Rendus, June 24, 1839. 



9.EMNA ARRHIZA. 



J. F. Hoffmann has instituted a series of observations to prove 

 that Lemna arrhiza is a constant species ; he observed the plant for 

 two years separated from all foreign mixture, and never saw indivi- 

 duals produced which were of a different species. He also observed 

 for several years the other common species of Lemna, and never found 

 anything that could be compared to L. arrhiza, nor have any inter- 

 mediate forms been discovered. — Tijdschrift v. naturl. Geschiedenis 

 en Physiol, iv. p. 282. 



