ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 421 



to pressure from the migrating eye. Correlated with this is an increase 

 in the distance between the eyes and the brain, caused by the growth 

 of the facial cartilages. The migrating eye moves through an arc of 

 about 120 degrees in about three days. The skeletal and nervous 

 changes are carefully described. It may be noted that the only well- 

 marked asymmetry in the adult brain is due to the much larger size of 

 the olfactory nerve and lobe of the ocular side. 



Thyroid of Lamprey.* — A. M. Eeese gives an account of the struc- 

 ture and development of the thyroid gland in Petromyzon (two or three 

 species), from the stage when it appears as a simple pit or groove of 

 the pharynx on to the adult condition. The adult has a paired basilar 

 or salivary gland of which no trace was seen in even the oldest larva, 

 but it seems possible that this is developed from the anterior part of 

 the larval thyroid, or from the pair of deep ciliated grooves which run 

 forward from the opening of the thyroid in the larva, and are not pre- 

 sent, as such, in the adult condition. The similarity in the secretion 

 of the larval thyroid to the secretion and function of a salivary gland 

 seems to support this view, but the author hopes soon to find evidence 

 of the existence or absence of this relation. 



Reproduction of Gerardinus decemmaculatus.f — N. Zolotnisky has 

 made some observations on this viviparous South American Cyprinodont. 

 It seems that the ventral fin is used as a penis ; reproduction may occur 

 four times a year, at irregular intervals ; the female excitement before 

 parturition is great ; there is a pause of 10-15 minutes between the 

 liberation of each pair of larvae ; the male seems to act as a sort of 

 accoucheur. The author's most remarkable report is that the female 

 can bring forth two sets of young in the absence of the male; he 

 urges experts to look into the matter. 



Development of Excretory Organs in Gymnophiona4 — A. Brauer, 

 in his third memoir on Gymnophiona, describes the development of the 

 pronephros and mesonephros in Hypogeoplm rostratus, and discusses the 

 difficult morphological questions involved. 



Hermaphroditism in the Herring. § — T. Southwell notes this 

 rather rare occurrence. The ovary had two lobes, and was anterior 

 in position ; the testis was a single mass, posterior in position. Both 

 bodies were fully matured, and had a healthy appearance. 



Argument for the Use-Inheritance Interpretation. || — W. Kidd 

 believes that " certain inherited characters of animals can only be in- 

 terpreted by considering them to have arisen in ancestors of those 

 animals by use or habit." His argument has reference to the disposition 

 of hair in mammals, which he regards as more adequately interpreted 

 on a dynamical theory of use-inheritance than by the selectionist 

 formula. 



* Proc. Acad. Sci. Philadelphia, 1902, pp. 85-112 (4 pis.), 

 t Arch. Zool. Exper., ix. (1901) Notes et Revue, pp. lxv.-lxxi. CI fig.)- 

 J Zool. Jahrb., xvi. (1902) pp. 1-176 (20 pis. and 85 figs.). 

 § Ann. Nat. Hist., li. (1902) pp. 195-6. 



|| Use-Inheritance. Illustrated by the direction of Hair on the bodies of animals. 

 London, 1901, 8vo, 47 pp. and 16 figs. 



