BOOK KEVIEWS. 



83 



Many of his adventures and experiences are most interesting, for he 

 travelled in many dangerous and out-of-the-way places, and describes, 

 with almost photographic accuracy, the ferocious insects, the flora, the 

 particularly exasperating Indians and other inhabitants. 



The scattered references to Orchids, Palms, Ferns, Bromeliads, 

 Melastomaceae and other interesting flowers and trees are often valuable. 

 He was an enthusiastic collector in a botanist's paradise and took every 

 advantage of his opportunities. We must allude also to the full account 

 of the rubber trees, and of the methods of preparation and collection, as 

 well as to his painful and dangerous search for Cinchona seedlings and 

 the successful transport of these specimens from their original home to 

 the seaport from which they eventually reached British India, where their 

 descendants are now flourishing. There are valuable accounts also of the 

 narcotics and stimulants in common use amongst the Indians. 



His sketch of the vegetation of the Amazon valley is exceedingly clear 

 and compares favourably even with the recent descriptions of Dr. Ula. 

 Indeed one is often apt to forget that these notes are forty years old, and one 

 cannot help wishing that he had worked out several problems of which 

 he evidently knew a great deal more than can be deduced from his rough 

 notes. 



The floating-islands of the Amazons, composed of grasses which are 

 sometimes forty-five feet long, seem to resemble similar vegetations from 

 the Nile and the Ganges. He has much of great interest to say also on 

 the different forests in the Amazon's valley, which are very clearly 

 distinguished and described. 



There are all sorts of questions connected with anthropology, zoology, 

 geology and meteorology, which are discussed in this work. There is, e.g., 

 a very full history of the Warrior-women or Amazons, of Valverde's still 

 secret treasure-store, and of the picture writing of the Indians which is 

 found etched on rocks at many points in the valley. 



But the most interesting part of the volume refers to those ferocious 

 ants which occupy, or perhaps we should say which dominate, the forests 

 of Hylaea. Spruce does not exactly say that they form the ant-gardens 

 by carrying seeds and earth to the forks of the branches, but he alludes 

 to them and very likely did not care to set down what he thought. The 

 Paper on ant-agency, which was written in 1869 and is now published for 

 the first time, is, however, of the greatest scientific importance, and it 

 should be carefully studied by every naturalist. 



There is a certain Melastomaceous genus, Tococa, of which there are 

 twenty-four or twenty-five species in the Amazons. One or two of these 

 are entirely submerged in the annual inundations, and these have no ant- 

 homes, but all the others, none of which are ever completely covered by 

 the water, possess peculiar sac-like swellings between the vein-forkings. 

 These are inhabited by ferocious ants which form an efficient bodyguard 

 to the plant. So far as these observations go, they simply add to the 

 already long list of ant-guarded plants. But Spruce in his original Paper 

 states that he examined half-grown plants, and saw that the sacs begin 

 to form long before any ants touch them and proceeds to draw the 

 important conclusion that these swellings or sacs are inherited and art> 

 the result of long continued generations of ant-visitors. 



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