174 SUMMARY OF CUKKENT KESKAKCHES RELATING TO 



tree, from which all the extant mammalian types are derived by modi- 

 fication of the pattern through migration, does not exist in the commonly 

 predicated form of a concrete and fixed morphological entity. It had 

 no reality in any definite ancestral structure, save in the sense that the 

 primitive reptilian lung and its phyletic derivative, the mammalian 

 endodermic primordium, both retain the potency of development by 

 selection into the type demanded by the environment. In place of the 

 mythical common ancestral bronchial tree appears a living plastic 

 organization, responsive to the changing demands of biological evolution 

 and replete with answers to the modern problems of morphogenetic 

 enquiry. J. A. T. 



Transitory Polydactylism. — J. A. Pires de Lima (Gomptes 

 Rendus Soc. Biol., 1920, 83, ] 190-2). Attention is called under 

 this title to the occurrence in new-born children or infants of digitiform 

 nodules which do not last, being attached only by a filiform stalk. The 

 author thinks that they are often overlooked, and that their occurrence 

 increases the number of cases of hyperdactylism. In some cases they 

 bear a distinct nail, but Httle is said in regard to their internal structure. 



J. A. T. 



Temperature of New-born Camels. — E. Sergent and A. Donatien 

 {Gomptes Bendus Soc. Biol., 1920, 83, 1062-3). P'or some weeks 

 after birth the average rectal temperature of healthy young camels is 

 SS° C, not varying more than a fifth of a degree up and down. Bat, 

 as in adult camels, if there is illness, e.g. due to injection of trypano- 

 somes, there may be fluctuations of 5° in a few hours. The temperature 

 may rise to 40^ and sink to 34° when the animal is in a pathological 

 state. J. A. T. 



Reactions of Amphibian Cells to Croton Oil.— Eliot R. Clark 

 and Eleanor L. Clark {Amer. Journ. Anat., 1920, 27, 221-53, 

 15 figs.). A study of the reactions and changes of cells of the tail in 

 Amphibian larvas in response to injections of minute globules of croton 

 oil. It is a study of aseptic 'inflammation. Connective-tissue cells 

 manifest all grades of injury, depending upon their nearness to the oil. 

 Non-pigmented leucocytes move toward the globule and at a certain 

 distance become stationary, sending out many fine processes, which are 

 withdrawn and renewed continuously. Pigmented leucocytes are 

 more resistant and may touch the globules without losing motiUty. 

 Blood capillaries near the globule show thickening and vacuolization of 

 the endothelium, and, subsequently, narrowing of the lumen, with, in 

 many cases, retraction of the endothelium. Lymphatic capillaries also 

 show vacuolization of the endothelium, and their lumen may become 

 much distended, particularly if an oedema develops. Throughout the 

 inflammatory reaction each type of cell maintains its specificity, and 

 ■ there is no evidence of transformation from one kind to another. 



J. A. T. 



Lipoid Content of Kidney Tubule.— Christianna Smith {Amer. 

 Journ. Anat, 1920, 27, 69-97, 2 pis.). Lipoids are characteristically 

 present in normal kidney cells either masked or free, and are shown 



