122 REVIEWS. 



the sentence would be understood by the learner. Paragraph 

 207, that roots grow in length at the extremities, " in propor- 

 tion as they find the requisite nutriment," might imply the 

 popular fallacy that they grow directly by means of what they 

 take in from the soil, which surely they do not, unless they 

 live in the manner of Fungi. To say that the starch, etc. in 

 a tuber or in a seed " appears to be a store of nourishment " 

 for the early growth of the buds or the embryo, is a remark- 

 ably over-cautious statement (how could these grow without 

 some store of elaborated matter to feed upon ?) ; nor does the 

 consideration that similar accumulations in the pericarps of 

 many fruits "perish long before germination," and so do not 

 nourish the embryo, afford to us any presumption to the con- 

 trary, even if we could not conceive — as we readily can — of 

 other final causes, some of them important to the continuance 

 of the species thereby subserved. 



The fourth chapter, on the Collection, Preservation, and 

 Determination of Plants, and upon Aberrations from the 

 ordinary type or appearance, is most excellent. 



DR. HOOKER'S DISTRIBUTION OF ARCTIC PLANTS. 



The immediate subjects of the treatise * are the Arctic 

 plants, of every phsenogaraous species known to occur spon- 

 taneously anywhere within the Arctic circle ; the geographical 

 distribution of which, so far as known, is carefully indicated : 

 1. Within the Arctic region, under the several divisions — 

 Europe, Asia, western America (Behring's Straits to the 

 Mackenzie River), eastern America (Mackenzie River to Baf- 

 fin's Bay), and arctic Greenland. 2. Without this circle, and 

 under the general divisions of north and central European and 

 north Asiatic Distribution, with three longitudinal subdivi- 

 sions ; American Distribution, with appropriate subdivisions ; 



1 Outlines of the Distribution of Arctic Plants. By Joseph D. Hooker. 

 Extr. Transactions Linncean Society, of London. Vol. xxiii. pp. 251-348. 

 1861. (American Journal of Science and Arts, 2 ser., xxxiv. 144.) 



