,8^. NOTES AND COMMENTS. ^b^ 



Hairs and Feathers. 



Another remarkable speculation that also necessitates further 

 independent research, appears in the current number of the Movpho- 

 logisches Jahyhuch (vol. xviii., pp. 717-804, pis. xxiv.-xxvi.). As is 

 well-known, it is the common belief that the hairs of mammals, the 

 feathers of birds, and the scales of reptiles are all epidermal structures 

 of a fundamentally identical character ; but after an elaborate study 

 of the growth and development of these several protective coverings, 

 Dr. F. Maurer, of Heidelberg, now arrives at the conclusion that 

 hairs are, in every respect, distinct from feathers and reptilian scales. 

 He considers that they are homologous with the sensory points in the 

 skin of the Amphibia, or, at least, that they are outgrowths from 

 these points as bases. Referring to the fact that the characters of 

 the integument are of importance in classifying the great groups of 

 Vertebrata, Dr. Maurer thus concludes that his researches confirm 

 the supposition that the Mammalia are derived directly from the 

 Amphibia, and have not had any Reptilian ancestors. 



The Dawn of Life. 



Among recent discoveries in the rise and progress of the world of 

 life as a whole, naturalists will turn with perhaps most interest to 

 Dr. Charles Barrois' announcement of the discovery of Radiolaria in 

 the Archaean rocks of Brittany [Comptes Rendus, vol. cxv., pp. 326- 

 328, 1892). The so-called Eozoon proving to be most unsatisfactory, 

 another claimant to represent Pre-cambrian Life will be welcomed by 

 those who still hope to decipher the conditions of that remote period ; 

 and the evidence has been discovered under circumstances that have 

 long been thought to betoken organic agency. The fossils occur in a 

 fine siliceous matrix (phtanite) associated with fragments of graphite, 

 in the neighbourhood of Lamballe, C6tes-du-Nord. They have been 

 submitted by Dr. Barrois to M. Cayeux, who regards them all as 

 simple Radiolaria, of the family Monosphaeridae ; and a detailed 

 description is promised for an early date. 



The Chemist as a Stratigraphical Geologist. 

 While referring to progress in the study of fossils in France, we 

 must not omit to mention a remarkable — some might say fantastic — 

 conclusion recently arrived at by a chemist, M. Adolphe Carnot, in 

 the study of fossil bones by chemical analysis [Comptes Rendus, vol. cxv., 

 pp. 337-339). This author believes, in fact, that the relative age of 

 fossil bones can be ascertained by estimating the amount of fluoride 

 of calcium entering into their percentage composition. While admit- 

 ting that these fossils vary much in composition with the nature 

 of the matrix, M. Carnot concludes that " there exists a sufficiently 

 constant relation between the amounts of tiuoride and phosphate of 



