22 



SCIENCE. 



[N". S. Vol. XXII. No. 549. 



which sometimes occur on the leaves of various 

 plants. After a historical discussion of leaf- 

 intumescences as observed by other investiga- 

 tors, the author describes the experiments 

 which he made by spraying cauliilowers with 

 various chemical substances. He found that 

 by using ammonium copper carbonate he could 

 produce intumescences at will, varying from 

 minute papillae to large wart-like excrescences, 

 dependent upon the size of the drops of the 

 spray. Sections of these artificially produced 

 intumescences showed that the mesophyll cells 

 had become enormously enlarged, first lifting 

 up, and later rupturing the epidermis. The 

 giant cells were very thin-walled, and occurred 

 in hair-like rows in which the outer cells soon 

 died and became filled with air, while in those 

 lying deeper ' very much reduced chlorophyll 

 grains could be found.' 



By means of careful experiments the aiithor 

 concludes that the peculiar growth of these 

 cells is due to chemical stimulation of a kind 

 hitherto unrecorded. Attention is directed to 

 the fact that somewhat similar intumescences 

 containing giant cells are formed as a result 

 of insect punctures, which it is surmised are 

 due to ' some chemical influences exerted by 

 the parent insect, the egg, or the larva.' It 

 is to be hoped that the experiments which the 

 author has now in progress may throw addi- 

 tional light upon this interesting subject, espe- 

 cially the connection between these chemically 

 produced giant cells and those produced in 

 insect galls. 



THE CALIFORNIA POPPIES. 



Dr. E. L. Greene, of the United States 

 National Museum, publishes a revision of the 

 California poppies (species of Eschscholtzia) 

 in the June number of Pittonia. The paper is 

 a continuation of work begun more than 

 twenty years ago, and continued from that 

 time to the present. The result is somewhat 

 startling, even in this day of many species of 

 hawthorns and violets. We may well repeat 

 the author's remark, ' that the species are so 

 numerous, one might well regret,' which he 

 follows with this his own defense : ' but na- 

 ture has yielded them, doubtless even more of 

 them than are here enumerated.' All told the 



paper describes 112 species, about three fourths 

 of which are described here for the first time. 

 More than two thirds of all the species enum- 

 erated are annuals. 



THE SMUT-FUNGI OP NORTH AMERICA. 



Under the title of ' North American Ustil- 

 agineae ' Dr. G. P. Clinton publishes in the 

 Proceedings of the Boston Society of Natural 

 History (Vol. 31, No. 9) a paper of two hun- 

 dred pages on the systematic botany of the 

 smut-fungi of North America. The paper is 

 the result of ten years of work (the last two 

 years in the cryptogamic laboratory of Har- 

 vard University), during which the author has 

 engaged in : (1) economic studies of the 

 species found in Illinois, published in bulletins 

 47 and 57 of the Illinois Agricultural Experi- 

 ment Station; (2) systematic studies, of which 

 the present paper is the outcome; (3) the dis- 

 tribution of exsiccati, one century of which ap- 

 peared in January, 1903 ; (4) spore germina- 

 tion studies, now under way. 



In the present paper the specific descriptions 

 are based upon the author's examination of 

 the available material, which includes prac- 

 tically all of the European and American ex- 

 siccati. This insures a broader treatment 

 than the order has hitherto received at the 

 hands of fungologists. It is significant of the 

 conservative tendencies of the author that al- 

 though he describes 205 species and varieties, 

 he finds it necessary to make but nine new 

 species. Nor does he find it necessary to erect 

 any new genera, so that his ' new names ' are 

 but three. 



The order includes two families, Ustilagina- 

 CEAE, represented by Ustilago (72 species), 

 Sphacelotheca (16), Melanopsichium (1), Cin- 

 tractia (14), Schizonella (1), Mycosyrinx (1), 

 Sorosporium (9), Thecaphora (9), Tolyvos- 

 porella (8), Tolyposporium (2), and Testi- 

 cularia (1) ; and Tilletiaceae, represented by 

 Tilletia (19 species), Neovossia (1), Tuher- 

 cinia (2), Urocystis (12), Entyloma (127), 

 Burrillia (3), Doassansia (11), and Tracya 



(1). 



An admirable specific systematic list of host 

 plants ; a table showing the distribution of our 

 species in other countries; a list of the more 



