62 REVIEWS. 



delicate plants in our houses in winter, and in our grounds 

 in summer, comes from the dryness of the air. For this, the 

 Ward case affords a perfect remedy ; as nothing is easier 

 than to furnish a saturated atmosphere for those plants that 

 require it, or to supply and retain the degree of moisture 

 which suits any particular species. 



HOOKER AND THOMSON'S INDIAN FLORA. 



One half of this volume ^ is occupied by the Introductory 

 Essay, in which a series of important general topics, akin to 

 those discussed in the introduction to Dr. Hooker's New Zea^ 

 land Flora, are treated with equal boldness and judgment, 

 and with the same freshness and originality of illustration. 

 These are arranged under six general heads, namely : 1. The 

 object, scope, and design of the " Flora Indica." 2. General 

 considerations connected with the study of systematic botany. 

 3. The variation and origin of species, the effects of hybridi- 

 zation, and the geographical distribution of species. 4. Sum- 

 mary of the labors of Indian botanists. 5. Sketch of the 

 meteorology of India. 6. Sketch of the physical features 

 and vegetation of the provinces of India. To which two maps 

 are added : one of monthly isotherms, from Dove ; the other a 

 large and original map illustrating the physical geography of 

 India and its botanical provinces. A complete alphabetical 

 index to this part of the work is appended, as well as a detailed 

 table of contents. 



To enumerate even the principal points which are discussed 

 would require a space which we are unable now to devote to 

 this subject. Some of them we may hope to consider here- 

 after in other connections. Among the conclusions or sug- 

 gestions that strike us as most true and timely are : The great 



^ Flora Indica : being a systematic account of the Plants of British 

 India. "Vol. I. By J. D. Hooker and Thomas Tlionison. (Ranunatlacece 

 to FumariacetE.) "With an Introductory Essay. London, 1855. (American 

 Journal of Science and Arts, 2 ser., xxi. 134.) 



