'2-t SU-M-MAKY OF CUKRl':NT RESEARCHES RELATING TO 



that is, a change produced in the lens of the uterine young which in 

 turn has induced a change in the lens-producing constituents in the 

 germ-cells of these young — or as simultaneous changes in the eyes and 

 in the germ-cells of the young. In either case the inference is that 

 there is some constitutional identity between the substance of the 

 mature organ in question and its material antecedents in the germ. 



J. A. T. 



Amnion-formation in Bats. — A. Celestino da Costa {Mem. Soc. 

 roiiugaise ScL Nat., 11)20, 3, 1-51, 3 pis.). The formation of the 

 amnion in Miniopterus schreibersii shows the following phases : (1) The 

 appearance of a closed cavity in the embryonic disc, the upper wall of 

 which is the primordial amnion ; (2) the rupture of this wall and the 

 disappearance of the primordial amniotic cavity, which is replaced by a 

 tropho-ectoblastic space ; (3) the formation of an amnion and a defini- 

 tive amniotic cavity with ectoblastic folds. In some other bats, Muriirns 

 and the Xoctule, it is the same, except that the primordial amniotic 

 cavity is less definite. The primordial type of amniogenesis in Mam- 

 mals, like that of Minwpterus, is seen in guinea pig, Galeopithecus, 

 Tatusia, and Primates. The primitive cavity disappears, and is replaced 

 by a cavity limited by the amniotic folds in Microchiroptera, pig, rat, 

 and mouse. The primitive cavity may be absent or only hinted at, as in 

 Gymnura, mole, Tvpaia, Tarsius, rabbit, and Carnivores. As Hubrecht 

 showed, the afiinion and the trophoblast are independent. J. A. T. 



Case of Human Synophthalmia. — Sixto de Los Angeles and 

 Anastaoia Villegas {P/uUpjjiue Journ. Sc/., 1920, 16, 99-107, 2 pis.). 

 Description of a case of male synophthalmia l>ilentica in an almost 

 full-term foetus, probably of eight months. It is very remarkable in 

 the apparent al^sence of the external nares, the representation of the 

 mouth by a small triangular opening about 1"5 mm. in diameter, the 

 presence of a snout-like dark-coloured structure above the oral aperture, 

 the, peculiarly shaped ears situated almost horizontally at the anterior 

 part of the neck, and the absence of the median walls in the fused 

 orbital cavity. , J. A. T. 



Piebald Spotting in. Dogs. — C. C. Little {Journ. Heredity, 1920, 

 11, 1-4, 3 figs.). Two cases are reported which give direct evidence as 

 to the origin of spotted individuals, and suggest that a spotted race may 

 arise from a self race by mutation without passing through a series of 

 minute gradations directed by selection. J. A. T. 



Hereditary Tendency to form Nerve Tumours. — C. B. Davenport 

 {Proc' Nat. Acad. Set., 1918, 4, 21:)— 1). Multiple neurofibromatosis is 

 a rather rare condition, characterized by the appearance of numerous 

 sessile or stalked s^^•ellings or tumours of varying consistency and size, 

 containing one or more nerve fibres, or, if more deeply seated, enlarge- 

 ments of the perineurium of nerve trunks. They are due to cell 

 proliferations of the connective-tissue sheaths of nerves. The course of 

 the disease is influenced by metabolic changes in the body — e.g. those 

 associated with puberty and pregnancy, or by zymotic diseases. Associated 



