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76 Scientific Intelligence. 



were it not for the fact that at many places through the book, 

 the editors of the orders have made very grave changes in the 

 orders and suborders, without giving all the evidence in the case. 

 Many of the changes seem to us desirable, but even in these, the 

 plainest, the statement of the new relationships is not sufficiently 

 full for all readers, and it seldom compares favorably with the 

 fullness in other portions of this excellent work. 



Continuing our analysis of the treatment of the order, we come 

 next to a short but clear statement of the geographical and 

 paleontological relations of the order, and the subject closes with 

 a synoptical view of the subgenera. 



The same author treats the Pyrolas and associated plants under 

 one order, Pirolacew. The whole treatment is substantially that 

 just described. After the citation of authorities, and the descrip- t 



tion of the distinguishing features of the group, the writer pre- 

 sents an interesting account of the economy of these plants, and 

 passes, by the way of Pyrola aphylla, a partial saprophyte, or 

 humus-loving plant, to the Monotropas and their associates, all 

 of which are true saprophytes. There is a graphic account of the 

 structure of the roots of these plants and their attached fungi, 

 through the intervention of which it is supposed they obtain their 

 nourishment. The anatomical peculiarities are given with con- 

 siderable detail. There is one point with reference to the roots, 

 which should be very carefully examined in our species, namely, 

 their extraordinary power of enabling the plant to multiply by 

 adventitious buds f owned on them. We do not ordinarily look 

 for buds on roots. 



The author speaks particularly of the coloring matter held in 

 the tissues of these saprophytes and the effects of agents, especially 

 alcohol, thereon. In short, here as elsewhere, the editors have left 

 out very few facts which can interest the student, the subject of 

 cross-fertilization and the like, receiving much attention. All the 

 more important features throughout, which require illustration, 

 are clearly and copiously figured. The section on geographical 

 distribution is short and telling. It is followed by a paragraph 

 on the supposed relationships, which to our thinking is less satis- 

 factory even than that referred to under Clethraceae. The reasons 

 adduced for separating these plants from their old time allies, the 

 other Ericaceae, appear trivial in the extreme. But, of course, 

 these are questions of judgment. It seems, however, as if the 

 editor ought to have given all his reasons for this separation and 

 presented his case in full. It seems ungracious to allude to this, 

 but since the treatise is likely to occupy a place not tilled by any 

 other work on Botany, the most important portion of the subject 

 of classification should have demanded rather more space for its 

 elucidation. The treatment of the order closes with a grouping 

 of the genera into suborders, and a description of the genera 

 themselves. The generic descriptions are almost full enough to 

 warrant us in saying that in most instances, it would be possible 

 to use the work as a handy Genera Plantarum. 



