ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 183 



definite. In all these cases the inter-renal tissue remains in its larval 

 position in relation to the mesonephros — namely, in the form of irregular 

 masses about the renal blood-vessel. J. A. T. 



Thyroid and Parathyroid in Toad Tadpoles deprived of Pituitary 

 Body. — Bennet M. Allen {Proc. Ayner. Soc. Zool. in Anat. Record, 

 1920, 17, 324-5). Tadpoles without pituitary body, killed six months 

 after the operation, more than four months after the metamorphosis 

 of the controls, showed thyroid one-third of the actual size of normal 

 tadpoles of Bufo at metamorphosis, but they showed the normal propor- 

 tion to the size of the body. The parathyroid glands, on the other 

 hand, showed unusual size, both relatively and absolutely. J. A. T. 



Influence of Thyroid Extirpation on Toad Larvae. — Bennet M. 

 Allen {Proc. Amer. Soc. Zool. in Anat. Record, 1920, 17, 325). The 

 removal of the thyroid tends generally to check the differentiation of 

 somatic structures, such as stomach, kidney and bladder. But the 

 gonads are larger and farther advanced in the giant thyroidless tad- 

 poles than in the much younger metamorphosed controls. J. A. T. 



Development of Columella auris in Reptiles. — Edward L. Rice 

 [Proc. Amer. Soc. Zool. in Anat. Record, 1920, 17, 352-3). The 

 reptilian columella auris has been regarded {a) as of otic origin, (Jb) 

 as of hyoid origin, and (c) as derived from both. In embryos of 

 Eumeces there is evidence of a genetic relation of the proximal portion 

 of the columella to the otic capsule and of the distal portion to the 

 hyoid arch. Yet it seems as if the entire columella was a unit structure. 

 The seeming contradiction may be explained on the assumption that 

 columella, otic capsule, and hyoid arch are all three developed from a 

 continuous embryonic stroma and later differentiated into separate 

 skeletal elements. J. A. T. 



Development of Denticles in Sword-fish. — J. Thornton Carter 

 {Proc. Zool. Soc, 1919, 321-6, 3 pis.). The developing denticles in a 

 young Xiphias gladius consist of a cap of dentine and a pediment, con- 

 nected by a transparent area. Later on there is a formation of trabeculae 

 joining adjacent pediments. The pediments are seen to stand up above 

 the level of the surrounding bone, but this bone continues to thicken 

 and grow until its surface lies almost at the level of the transparent area. 

 The same is true in Blenny, Bream and Histiophorus. Tooth or 

 denticle, pediment, and connecting area are formed in all cases on the 

 surface of the same papilla. The bone to which the teeth or denticles 

 are attached is not independently developed, but is " an extension of the 

 denticle cone," so that the sharp line of demarcation drawn by Goodrich 

 between the tooth-bearing bones in Teleostei and the bases of placoid 

 scales does not exist. J. A. T. 



Hermaphrodite Green Lizard. — Noel Taylor {Proc. Zool. Soc, 

 1918, 223-30, 3 figs.). A specimen of Lacerta viridis showed testes 

 normal in shape and structure, but bearing stalked outgrowths contain- 



