Reviews — Clement Reid — Origin of the British Flora. 425 



of twenty years' work. The method of treatment adopted by the 

 author is such as to inspire the reader with confidence ; the greater 

 part of the evidence which is adduced being the result of painstaking 

 work by one who has proved himself not only an able geologist, but 

 a keen naturalist, thoroughly equipped by contact with Nature, under 

 varied conditions, to attack the problems which centre round the 

 origin of the British Flora. 



In the introductory chapter Mr. Eeid tells us something of his 

 methods of work : while availing himself of the assistance afforded 

 by the lierbaria of Kew and the British Museum, he soon found 

 himself compelled to collect his own material, especially seeds and 

 fruits, to compare with the fragmentary relics of the Pleistocene 

 vegetation. Making the most of his opportunities in the field, the 

 author paid special attention to such biological phenomena as the 

 dispersal of seeds, and other factors concerned in the struggle for 

 existence among our native plants, which might enable him to more 

 satisfactorily interpret the fossil records, and to appreciate the 

 complex agencies connected with the origin of the present flora. 



In chapter ii, entitled " The Present Flora of Britain," there are 

 many useful notes on the influence of climatal conditions and other 

 agencies of importance in determining the composition and dis- 

 tribution of the British flora. It is pointed out that Britain shows 

 signs " of a geographical distribution of plants largely independent 

 of that due to climate; or, perhaps we should say, not governed 

 by existing climatal conditions." One of the peculiarities of the 

 present flora, which it is difficult to understand, is illustrated by the 

 occurrence of Pyrenean plants in the West of Ireland and in 

 Cornwall and Devon. In speaking of the woodland flora Reid 

 refers to the probability of such trees as the Horse Chesnut, Spanish 

 Chesnut, Sycamore, Lime, and others, having been introduced by 

 the Romans, who were in the habit of planting trees round their 

 villas for shade and beauty. 



The interest of chapter iii, dealing with a subject which, if treated 

 fully, would occupy several times the space allotted to it, is con- 

 siderably increased by a number of new and interesting facts based 

 on personal observation. The spread of oak woods is no doubt 

 intimately connected with bird-agency ; the occurrence of oak 

 seedlings in various situations where no mammal would take the 

 fruits, and other facts, lead the author to conclude that rooks are 

 mainly responsible for the dispersal of acorns. 



Long-distance transport of large edible seeds may occasionally be 

 due to rare accidents rather than to special adaptation, as illustrated 

 by the following note : — " Some years ago I found in an old chalk- 

 pit the remains of a wood-pigeon which had met with some accident. 

 Its crop was full of broad beans, all of which were growing well, 

 though under ordinary circumstances they would have been digested 

 and destroyed." The avidity with which some of our native plants 

 occupy a newly exposed tract of ground is neatly illustrated by the 

 following description : — " When the new railway to Cromer was 

 made, the turf and top soil were pared off for a long distance, but 



