232 NATURAL SCIENCE. April, 1896. 



a representative Indian insectivorous bird. To some of these, in 

 freedom and in confinement, hungry and sated, he offered all sorts of 

 brightly-coloured and hairy caterpillars and butterflies, sometimes alone 

 and sometimes along with other less lurid creatures. This first con- 

 tribution gives the results of a series of such experiments. Sometimes 

 the birds certainly chose the plainly coloured, and presumably more 

 palatable, forms offered them ; sometimes they accepted and swallowed 

 those which no bird of a really cultured disposition should have 

 looked at. Perhaps, on the whole, the experiments showed a 

 preponderating rejection of brightly-coloured caterpillars, which 

 were frequently mauled but not swallowed. We look forward with 

 interest to a continuation of Mr. Finn's work. We are specially glad 

 that he has been able to correct observations upon birds in captivity 

 by observations on those at large. It is a not unnatural supposition 

 that birds in a cage should be in the position of the lady in the ditty 

 who " wanted something to play with," and we do not think that it 

 would upset the supposed relation of bright colour to unpalatability 

 were captured birds to show a catholic taste. 



The Embryology of Platypus. 



In the ninth volume of the Proceedings of the Linnean Society of 

 New South Wales, Messrs. J. P. Hill and C. J. Martin give an account 

 of Platypus embryos, taken from the intra-uterine egg. It will be 

 remembered by probably most people except Mr. Caldwell himself, 

 that the material collected by Caldwell has afforded us very little 

 information. The present observers obtained two eggs from the 

 left uterus of a female, and they give a description and excellent 

 figures of the results they got by surface examination and serial 

 sections. The most novel feature seen in surface view was the 

 extent to which segmentation had proceeded, although the embryo 

 was still lying almost flat on the surface of the yolk. Seventeen 

 somites were formed, and the only trace of pinching from the surface 

 of the yolk was a very shallow head-fold. The hind-brain showed 

 four well-marked neuromeres, corresponding to those described by 

 Orr for the hind-brain of the lizard, with the difference that in the 

 lizard the medullary folds have met when the neuromeres appear, 

 while in Platypus the hind-brain is still flat at this stage. An inte- 

 resting feature in the embryo was that the wolffian duct appeared to 

 have an ectodermic origin. 



