488 THE POPULAR SCIENCE MONTHLY. 



nating as they may be to chemists, would offer few charms to the gen- 

 eral reader. 



Since 1841 Dr. Asa Gray has devoted such leisure as he could 

 command to his great work " The Flora of North America," a labor 

 the magnitude of which only an experienced botanist can appreciate. 

 Mr. Watson, Curator of the Herbarium, is assisting Professor Gray, 

 and at present is classifying the flora of California. The new series 

 of botanical text-books, edited by Dr. Gray, will shortly be completed. 

 The titles will be as follows : 



1. " Structure and Morphological Botany of Phaenogamous Plants," 

 by Dr. Gray. 



2. " Physiological Botany " (Vegetable Histology and Physiology), 

 by Dr. Goodale. 



3. " Introduction to Cryptogamous Botany," by Professor Farlow. 



4. " Natural Orders of Phsenogamous Plants and their Special Mor- 

 phological Classification, Distribution, Products," by Dr. Gray. 



One of the most recent of Dr. Gray's botanical contributions to 

 the Academy of Arts and Sciences was a paper on the " Characters of 

 some New Species of Compositse in the Mexican Collection, made by 

 C. C. Parry and Edward Palmer," and a notice of " Some New North 

 American Genera, Species, etc." 



Professor Farlow's work in cryptogamic botany is doubly inter- 

 esting on account of its direct practical application. At the Bussey 

 Institution Professor Farlow has been investigating the diseases of 

 plants, and latterly has been engaged upon algse and fungi. Among 

 his recent work is a paper on algae for the United States Fish Com- 

 mission, an examination of the causes of onion-smut and the diseases 

 of trees for the Board of Agriculture, and an investigation of the alga? 

 producing disagreeable tastes and smells in water, for the State Board 

 of Health. His work resolves itself, speaking generally, into two kinds 

 one, the abstract descriptions and arrangements in families of alga? 

 and fungi, and the other the detection of fungi in disease. As an 

 example of the first, there is a European species of algse which consti- 

 tutes the green scum on stagnant water. Several different varieties 

 may be found in different places, but they have all been discovered to 

 belong to the same family. To illustrate the second, there is a certain 

 kind of fungus on cedar-trees, but this has been ascertained to be only 

 a first stage, and the fungus in its second stage is found upon several 

 members of the apple family. 



Professor Wolcott Gibbs has been carrying on researches on com- 

 plex inorganic acids, and Professors Lovering and Trowbridge have 

 been conducting purely physical investigations. Professor Trowbridge 

 has introduced a method of instruction that necessitates a large amount 

 of original research on the part of his students. This consists of lec- 

 tures, given by the students instead of by the instructor, to the class. . 

 Although all the work at the Observatory really comes under the 



