7 o6 SCIENCE PROGRESS 



In this volume he tells the story of how, by taking full advantage of very excep- 

 tional circumstances, he was enabled safely to bring to England sufficient seeds, 

 which, later, at the botanic garden at Heneratgoda in Ceylon, became the 

 parent stock of the present flourishing industries in Ceylon, British Malaya, India 

 and other parts of the world. It is lamentable to find, owing to the author's 

 original reports not being readily accessible to planters and others, that erroneous 

 ideas about the requirements of the plant obtained credence, and much valuable 

 time was lost in laboriously gaining, by slow and often costly experience, know- 

 ledge which was already well known, at any rate to Mr. Wickham. The idea, for 

 instance, that Hevea thrives in swampy ground, although quite incorrect, persisted 

 for a very long time, and even yet has not altogether disappeared. 



Concerning the mode of cultivation Mr. Wickham advocates wider planting 

 (33 x 23 f eet ) tr) an is as yet generally adopted, and is in favour of setting the young 

 plants in small cleared areas in forest land, without going to the expense, with the 

 accompanying destruction of the humus, of clearing and burning all the standing 

 vegetation as is usual. The authors views on tapping and curing will also be of 

 great interest to all engaged in rubber producing. The book, small though it is, 

 contains a good deal of repetition, but it deals with the subject throughout in a 

 very practical manner ; and the author's views, considering his great experience 

 with the plant, both in its native home and also on estates, are well worthy of 

 careful attention, not the least on those points in which he is not in agreement with 



current practice. 



W. G. Freeman. 



Practical Zoology. By T. J. and W. N. Parker. [Pp. xii. + 624.] (Mac- 

 millan & Co., 1908. us. 6d.) 



A SECOND edition of this well-known text-book has been issued. An account of 

 Nereis and of Monocystis has been added ; and Obelia has been substituted for 

 Bongainvillea. It is a very serviceable introduction to the study of Zoology, and 

 contains a great deal of valuable information. 



But there are certain new points which we think ought to have been alluded 

 to, and some of the illustrations in it might have been omitted. 



Gaupp's masterly monograph on the Frog has placed within our reach an 

 account of the anatomy and physiology of the frog's heart which is far in advance 

 of that with which we have had to be content hitherto. Again, the account of the 

 formation of the segmentation cavity in the frog is most meagre. Morgan, in his 

 " The Development of the Frog's Egg," has placed what is known on this subject 

 within easy reach of all. Some account of the development of the mammal and 

 of the homologies of its foetal membranes would have added to the interest of the 

 book. 



There are, we think, rather too many diagrams and names printed in italics or 

 black type. Names should not be emphasised. For example, to call the stage 

 before the gastrula of the frog both a polyplast and morula does not enlighten 

 the student. The elementary student is apt to think that the names are the 

 important things, and in labelling his drawing of a dissection will very often 

 make an arrow going from an organ to its name, as if the name were the goal. 

 Text-books are largely responsible for this inversion of the real relative importance 

 of the two. 



Nevertheless, the authors of this book have, and express, very sound opinions 

 on the relative importance of text-book knowledge and the knowledge obtained 

 from dissection of animals. They also retain what so many zoologists have lost, a 



