ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 155 



are found all the year round in unaltered number, afnd with the same 

 staining reactions. They do not change with age, sexual activity, or 

 stiite of nutrition. They were not found in other Anura, in Urodela, or 

 in reptiles. An acidophilous variety of epithelial cells occurs, however, 

 in some other glands of internal secretion, such as the hypophysis. 



Skin of the Carp.* — Adolf von Grunelius finds that young carp, ten 

 days old, <S mm. long, have a very thin, as yet undifferentiated epidermis, 

 and no trace of corium. Later on, the first hint of the corium is a fine 

 structureless lamella. There is some evidence that epidermis cells share 

 in the formation of the corium. 



The differentiated epidermis shows three different layers of cells. 

 The basal layer seems to arise from interaction between the epidermis 

 and corium. 



The development of the scale begins from a scale-primordium lying 

 between the epidermis and the corium. Above this primordium there 

 are basal epidermic cells, which the author interprets as a rudimentary 

 enamel organ. They subsequently disappear when hard substance is 

 formed in the scale-primordium. There was no evidence that the ecto- 

 derm shared in the scale-making. 



Changes in Chondriosomes in Pathological Conditions.t — J. 0. 



Wakeliu Barratt finds that the mitochondria of hepatic cells in pigmented 

 degeneration of the liver assume a brownish-black colour and form the 

 pigment-granules characteristic of this condition. In severe haemo- 

 globinsemia the chrondriosomes of the cells of the convoluted tubules are 

 more readily demonstrable than in the normal condition, their staining 

 capacity being increased. In this condition the mitochondrial elements 

 reach an abnormally large size and are observed to take part in the 

 elimination of hsemoglobin. In pathological conditions in which rapid 

 cell-proliferation is occurring, the chondriosomes of the prickle layer of 

 the epidermis appear of large size, and stain with unusual facility, de- 

 tails of their structure being readily observable. In this respect they 

 constrast with normal epidermal chrondriosomes, which stain imperfectly. 



Superficial Vascular System of Amphioxus.J — B. Mozejko caUs 

 attention to a delicate superficial network of vessels beneath the skin of 

 the lancelet. It is independent of the segmental veins described by 

 Langerhans. There are metameric veins corresponding to the myotomes, 

 and intermuscular veins, and numerous collaterals which form a net- 

 work. Between two metameric veins there is a network of capillaries. 

 The whole system seems to correspond to a similar system in Ammocoete 

 larvae. It may also be compared, to the " lateral vascular system " of 

 Teleosts, and to the superficial lymphatic system in Amphilnan larvae. 



Cartilaginous Tissue in Invertebrates.§ — M. Nowikoff deals with 

 the head cartilage of Cephalopods, the subradular cartilage of Gastropods, 



* Jen. Zeitschr. Naturw., xlix. (1912) pp. 119-48 (3 pis. and 16 figs.). 



t Quart. Journ. Micr. Sci., Iviii. (1913) pp. 553-66 (11 figs.). 



X Anat. Anzeig., xlii. (1912) p. 477. 



§ Zeitschr. wiss. Zool., ciii. (1912) pp. 661-717 (3 pis. and 13 figs.). 



M 2 



