ZOOLOGY AND BOTANY, MICROSCOPV, ETC. 573 



Pigment Network in Nurse Frog.* — A. Borrel maintains that in 

 larvae of AJ//tes ohstPtn'rans there is a network in which pigment circu- 

 lates, and from which pigment-cells are set free. In embryos still within 

 the egg, transitions may be seen between pigment-cells which have 

 become free, and others which are still fixed portions of the network. 



Peculiar Erythrophores in Skin of Teleosts.t — E. Ballowitz 

 describes peculiar erythrophores in various decorative fishes {Fundidus 

 gularis, F. sjostedti, Haplochilus chaijeri, Hemlchromis bimaculntus, 

 Pantodon buchholzi). They differ notably from other erythrophores, 

 since their red or red-brown piLiment is not extracted or changed by 

 alcohol. It is bound up with stable granules and must be different from 

 the common red lipochrome which is dissolved out in alcoliol. The 

 minute structure of these erythrophores is desciibed at length. 



Epidermis of Trachypterus taenia. J — D. Kaschkaroff describes the 

 peculiar epidermis of this ribbon-fish. There are no scales. The 

 epidermis that seems at first to be absent has a structure like that of the 

 notochord gelatinous substance in lower fishes. The component cells 

 are large — a little smaller than the vesicular chorda-cells in the same 

 animal. They are practically empty, the nucleus vsdth a little cytoplasm 

 Ivins: ao'ainst one wall. The boundaries are smooth : there seem to be 

 no intercellular bridges ; the cells are rarely isolated. Very flat cells 

 cover the periphery and show a superficial sculpturing of ridges. It is 

 probable that the epidermis serves as an elastic supporting tissue, com- 

 pensating lor the weakness of the fins which have no bones. 



Relation of Myofibrils to Tendon-fibrils. § — T. Peterfi has studied 

 this in frog, mouse, and larval salamander. He finds that most of the 

 muscle-fibres are terminally bound by an unbroken sarcolemma. This 

 consists of a hyaline membrane (or matrix) and a network of connective- 

 tissue fibrils. The tendon fibrils take their origin from the connective- 

 tissue fibrils of the sarcolemma. The appearance of a continuity 

 bewteen muscle-fibrils and tendon-fibrils may arise (a) if the sarcolemma 

 fibrils are projected on the muscle-fibre ; (b) if the end of the muscle- 

 fibre is so pointed that the connective-tissue fibrils on its surface cannot 

 be optically isolated from the terminal portions of the myofibrils ; (c) if 

 the end of the muscle-fibre is irregular and the sarcolemma zig-zag ; 

 (d) if in the contraction th^ sarcolemma be pressed down by the con- 

 nective-tissue network and drawn into the muscle-fibres; and (e) if during 

 relaxation the myofibrils be variously extended and push the sarcolemma 

 before them. The author cannot agree with Schultze and Loginow. 



Connexion between Tendon-fibrils and Muscle-fibrils. || — M. A. 

 Yan Herwerden ha-s studied this in the salamander, and has convinced 

 himself that the sarcolemma is a definite boundary through which fibrils 

 do not pass. On the one side are the tendon-fibrils, on the other side 

 muscle-fibrils ; but there is no continuity. Schultze and Loginow have 



* CR. Soc.Biol. Paris, Ixxv. (1913) pp. 211-14 (2 figs.). 



t Arch. Mikr. Anat., Ixxxii. (1913) pp. 206-19 (1 pi.). 



X Anat. Anzeig., xliv. (1913) pp. 214-18 (3 figs.). 



§ Arch. Mikr. Anat., Ixxxiii. (1913) Abt. 1, pp. 1-42 (3 pis. and 18 figs.). 



l[ Anat. Anzeig., xliv. (1913) pp. 193-7 (7 figs.). 



