6 NATURAL SCIENCE. July. 



embryos, and found among them well-marked traces of all the 

 peculiarities ; in some cases, indeed, the foetus showed the Veddah 

 and Hindu peculiarities in an absolutely typical form. He believes, 

 therefore, that the bent tibial facets and accessory articulation with 

 the astragalus, and so forth, are not instances of an inheritance of 

 acquired characters, but are an atavistic inheritance of conditions 

 once universal. 



Dr. Retzius believes, in fact, that a reversed account of the true 

 state of affairs has been given. It is modern conditions, the habit of 

 sitting on chairs, and so forth, that is gradually altering the typical 

 character of the bones of the lower limbs. The modern foetus retains 

 the ancestral condition, and the modern characters are acquired later 

 in life. On the other hand, although we do not quite follow his argu- 

 ment, he thinks that an instance of the existence of the Lamarckian 

 factor is to be found in the changes occurring in ourselves. He is 

 severe, however, on those writers who attach great importance to the 

 changes produced by mechanical factors, by strains and stresses and 

 so forth. He insists upon the historical factor, upon the internal 

 forces that direct the development. We commend his chapter, of 

 which this is only the slightest sketch, to our readers who are 

 interested in heredity. 



Warning Colours and Mimicry. 



Mr. Frank Finn has continued his experimental investigations 

 into the palatability of warningly coloured insects {see Nat. Sci., vol. 

 viii., p. 231). His most recent experiments are published in the 

 Journal of the Asiatic Society of Bengal (i8g5, p. 2). Using the common 

 garden lizard of India, Calotes versicolor, both in captivity and in 

 freedom, he tempted its appetite with all manner of plain and parti- 

 coloured insects. The details of each experiment are given, and 

 they certainly corroborate Mr. Finn's conclusion that, in the case of 

 butterflies, at any rate, warning colours and unpalatability so far as 

 lizards are concerned do not go together. Mr. Finn was careful to 

 use common butterflies, and the lizard in question is accustomed to 

 take butterflies in the natural state. We hope that Mr. Finn will 

 proceed with his experiments. Warning colours, mimicry, and so 

 forth are among the chief contributions of the much-praised field- 

 naturalist to the theory of evolution, and, like many of the conclusions 

 of the field-naturalist, they require the more careful investigation of 

 the trained expert. 



American Entomology. 



In our June number we gave some account of the Chinch-bug, 

 Blissusleucoptcrus. Mr. S. A. Forbes' Report on Noxious and Beneficial 

 Insects of the State of Illinois for 1893-4 ^^ chiefly devoted to details of 

 experiments in innoculating Chinch-bugs with fungoid disease. The 



