1908] CURRENT LITERATURE 399 
Development of Ulva.—The development and conjugation of gametes and 
also the germination of the zygote are described by ScHILLER*4 for both living 
and fixed materials. Three kinds of gametes are found in Ulva and also in 
Enteromorpha: (1) megagametes or giant gametes, which do not conjugate and 
are incapable of development; (2) parthenogametes, of medium size, which germi- 
nate into normal plants without any conjugation; and (3) microgametes, which 
are smaller than the parthenogametes and which produce new plants only after 
conjugation. The relation between the nucleus and the protoplasmic mass in 
the various gametes is believed to be the reason for the differences in behavior.— 
C S J. CHAMBERLAIN. 
Paleobotanical technique.—The veteran and distinguished Swedish paleo- 
botanist NarHorst has contributed remarkably to the technique as well as to 
the facts of that science. His most recent contribution to technique is in connec- 
tion with the use of collodion impressions of the surface of fossil plants for micro- 
Scopic study.?5 With the article are published photomicrographs made from 
such films, illustrating the structure of fossil fern sporangia, the epidermis of the 
leaves of ferns, and gymnosperms and angiosperms in a fossil condition. Even 
4 Cupressinoxylon yields results with this method.—E. C. JEFFREY. 
A Paleocene flora.—M. PrerreE Marty of the Royal Belgian Museum of 
Natural History has published a memoir?® on the Paleocene flora of Trieu de 
Leval. Perhaps the most interesting feature of this publication is the discussion 
of the phylogeny of the important genus Quercus, 4 propos of the new species 
Dr yophyllum levalense. The latter has chestnut-like leaves and the author con- 
Cludes that among the living oaks it has its nearest affinities in those ancestral 
forms persisting in India, Japan, and the East Indies. The flora as a whole, 
with the above exception, presents a marked resemblance to that at present 
*xisting in northern South America.—E. C. JEFFREY. 
ae and Fungi of lowa.—BucHANAN?’ has brought together in convenient 
form, with keys, a list of the algae reported from Iowa, based upon the study of 
peaerous recent collections. The list includes 180 species, and the bibliography 
of “Towa Algae” includes nine titles. . 
_ The same thing has been done for the Erysiphaceae of Iowa by ANDERSON,’ 
including of course a complete list of hosts. ‘The recognized species and varieties 
sop 28, involving 35 synonymns; while the hosts reported number 187.— 
ba ae, Dr. Joser, Beitrage zur Kenntniss der Entwickelung der Gattung 
- Sitzungs> r, Kaiserl. Acad. Wiss. Wien 116:1-26. pls. I, 2. 1997- | 
Unt *S NaTHorsT, A. G., Ueber die Anwendung von Kollodiumabdruecken bei der 
*rsuchung fossiler Pflanzen. Arkiv fér Botanik 7:no. 4. 19°7- 
ers, Prerre, Mém. Musée Roy. d’Hist. Nat. Belgigique 
Sci oN, RoBeRT EartE, Notes on the algae of Iowa. 
. “PP. 40 (repaged). 1908. 
™ ANDERson, J. P., Iowa Erysiphaceae. Idem 14:pp- 34 (repa ed). 1908. 
521-51. 1908. 
Proc. Iowa Acad. 
