1900] | CURRENT LITERATURE 417 
facts presented, and such deductions as he makes in regard to climate are 
conservative. ‘The last chapter will be somewhat startling to many readers, 
as Zeiller thinks there is very little evidence from fossil plants in favor of 
gradual evolution. He states that in almost every case, species, genera, 
families, and groups appear highly specialized and in their permanent form 
from the first. So-called intermediate forms like Cheirostrobus appear long 
after the forms they are supposed to connect. Genera and species that vary 
now have always varied, and the limits of variation now and in the past have 
been the same and definitely prescribed. In short, Zeiller believes that the 
evolution of all groups is a matter almost purely of speculation. Doubtless 
most botanists will fail to accept Zeiller’s views as to evolution, and yet it 
may be well to put a brake now and then to unlimited speculation ; a perusal 
of Zeiller’s final chapter certainly compels one to do that.—H. C. CowLes. 
Plant diseases. 
__ In 1882 the first edition of Robert Hartig’s Lehrbuch der Baumkrankheiten 
appeared. This book met with instant favor and was at once recognized as 
astandard reference work for diseases of trees, especially those caused by 
the higher fungi. In 1889 the second edition appeared and the favorable 
reception accorded the first edition was repeated. The third edition has 
now been issued — this time, however, with a changed title.’ The change of 
name from Baum-to Pfhlanzenkrankheiten would naturally lead one to expect 
that the discussion of the subject had been extended so as to include non- 
woody plants not considered in the previous editions. This is not the case, 
however, for practically the same plants are treated in the edition before us 
asin the others. The work is still confined in the main to diseases of woody 
Plants. This is shown by the fact that of the 280 figures only eleven illustrate 
diseases or parasitic fungi of non-woody plants. Thirty-one pages are given 
to the discussion of the rusts affecting woody plants and a little over two 
_ Pages to those affecting non-woody plants. Aside from about six pages given 
_ tosmuts and short references under Claviceps purpurea, Cystopus candidus, 
- Pp lasmodiophora brassicae, and the bacterial diseases of hyacinths and potato, 
_ the other notes on diseases of non-woody plants caused by fungi are only 
incidental, The book is divided into five main headings, viz.: (1) injuries 
_ Caused by plants; (2) diseases caused by atmospheric pein: ud 
_ €ases caused by the action of injurious substances; (4) diseases due to ¢ 
ts: (5) wounds, With the exception of one or two paragrapas, 
lants 
Owever, consideration is given under the last four heads to woody p 
only, 
SHARTIG, RoBERT: Lehrbuch der Pflanzenkrankheiten. Fiir Botaniker, S98 
‘ leute, the Noise und Gartner. Dritte, vollig neu bearbeitete Auflage se me 
E Mtthes der Bcccabeask sual 8vo. pp. ix-+324. Ags 280. pl. 1 (colored). 
- Berlin: Julius Springer. 1900. : 
