370 NATURAL SCIENCE. June. 



birds, several of which are known as fossils, inhabits the most 

 secluded parts of the forests of South America, and it is probable that 

 it is owing to its retiring habits it has outlived its congeners, as well 

 as to the fact that, feeding as it does upon wild arum leaves, its flesh 

 acquires so offensive a flavour as to have gained it the name of the 

 ' stink ' bird, and to render it entirely unfit for food. It is a large 

 bird, almost as large as a peacock, in fact, but is very seldom seen. 

 Oftener its loud wailing cry is heard. 



" The chief peculiarity of the Hoatzin consists in the fact that 

 when it is hatched it possesses four well-developed legs, the front pair 

 being of a reptilian character. The young birds leave the nest and 

 climb about like monkeys over the adjoining limbs and twigs, and act 

 and look more like tree toads than birds. After hatching, the modifi- 

 cation of the fore-limbs begins, the claws of the digits falling off, and 

 the whole of the claw-like hands becoming flattened, change into 

 wings. After this modification has taken place, feathers begin to 

 grow, and in a short time not a vestige remains of its original 

 character. The adult birds not only have no claws upon their wings, 

 but their thumbs, even, are so poorly developed that one would hardly 

 suspect that in the nestlings we have the nearest approach to a 

 quadruped found among existing birds." 



In Post Octavo. 



In view of recent attempts to resuscitate the quarto Transactions of 

 the Geological Society of London, an editorial by Professor J. C. Branner 

 in the February-March number of the Journal of Geology may be read 

 with profit. On behalf of the field-geologist it pleads for books with a 

 small page. Big books cannot be carried in the field, and are incon- 

 venient even in the library. " Small books will serve equally well 

 the man in the office or in the field, in camp or on horseback. The 

 taking of books into the field should be encouraged ; our laboratory is 

 there, and there is no other place in which a book can render such 

 lively service." So far as descriptions of topographic geology are 

 concerned, there is much force in these remarks, and there is no 

 doubt that experience of books in general confirms the arguments of 

 Mr. Branner. A study of the evolution of scientific periodicals and 

 the publications of learned societies has already been made by 

 some ingenious Americans, and it has been shown that the octavo 

 form has in nearly all cases survived as the fittest. "There is 

 no advantage in very large type," says the Journal of Geology. " There 

 is no advantage v/hatever to a working geologist or to a student for 

 his books to have large pages, wide margins, or to be printed on 

 unnecessarily thick paper." True though these statements are, their 

 occurrence in the Journal of Geology is curious. Its current number of 

 128 pages, and weighing i2f ounces, contains about 51,600 words, 

 whereas our last number of 72 pages, and weighing 4|- ounces, 

 contains about 43,000 works. In these estimates, illustrations and 

 blank space are reckoned as words. To put it another way, an 

 average page of Natural Science, which is of the same height but 

 six-sevenths of the width, contains just half as many words again as 



