ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 187 



cellular notockordal sheath ; (b) a tract of sclerotome which is trans- 

 formed directly into cartilage ; and (c) the intra-arcual membrane. 



Development of Enteron in American Alligator.* — Albert M. Reese 

 describes the development of the alimentary canal, with a brief descrip- 

 tion of the minute structure for each stage discussed. An account of 

 the development of the derivatives of the digestive tract is postponed. 

 No summary is given of the more important results. 



Development of Alpine Salamander.f — Hans Wunderer describes in 

 particular the development of the external form in Salamandra atra. He 

 describes the total unequal segmentation of the telolecithal ovum, the 

 gastrulation, the formation of the medullary groove and its closure, the 

 development of gill-arches and gills, and so on. An interesting general 

 result is that S. atra is in many respects nearer to Tritonidse and 

 Amblystomatidae than to S. maculosa. Its origin from the latter is out 

 of the question, and perhaps it is not a Salamandra at all. 



Production of Supernumerary Limbs in Amphibians. J — Eugen 

 Lissitzky has followed Tornier's method of cutting the primordia of the 

 limbs in young tadpoles, and thus inducing duplicity. Sometimes two 

 pelvic girdles were produced. His particular aim has been to enquire 

 into the minute structure of the supernumerary growths, but the main 

 results of this enquiry are held over. 



Development of Teleosts.§— Caroline Reis has studied the early 

 development of Amiurus nebulosus and a number of other types. 

 Among the conclusions reached we note the following. The embryo 

 develops mainly from the material at the posterior margin of the blasto- 

 derm, where the endoderm, the notochord, and the mesoderm are 

 established. There is a concentration of this embryo-forming material 

 towards the middle line. With the appearance of Kupffer's vesicle, 

 which forms the most posterior end of the endoderm, the most important 

 embryo-forming material reaches the longitudinal axis of the embryo. 

 What is left peripherally is used in forming the tail. 



Kupffer's vesicle does not remain where it appears, but is shunted 

 forwards during the formation of the end of the embryo from the 

 posteriorly coalescent marginal ring. A similar coalescence of the 

 halves of the marginal ring takes place at the opposite end. 



Development of Pigment-cells in Teleostean Embryos. || — L. Bolk 

 has studied this in Atherina, Alburnus, Box, Belone, and Lophius. Some 

 of the noteworthy points are the following : that the pigment-cells 

 appear very early ; that they are very regular in their arrangement ; that 

 they sometimes show a metameric character. Those that are metameri- 

 cally disposed arise in situ from unpigmented cells. Migration, however, 

 in the cutis was well seen in the tail end of the angler. 



* Smithsonian Misc. Coll., lvi. No. 11 (1910) pp. 1-25 (15 pis.). 



t Zool. Jahrb., xxix. (1910) pp. 367-414 (9 pis.). 



j Arch. Mikr. Anat., lxxv. (1910) pp. 587-633 (3 pis. and 3 figs.). 



§ Bull. Acad. Sci. Cracovie (1910) pp. 521-42 (3 pis.). 



|| Arch. Mikr. Anat., lxxv. (1910) pp. 414-34 (1 pi. and 6 figs.). 



