366 SCIENCE. 
imbricaria). Other species of oak occur on 
the Point. The two trees were a few rods 
apart; their trunks were about twelve and 
twenty inches in diameter. The other sta- 
tions known are Cincinnati, Brownsville, 
Licking couuty (the tree cut down in 1892, 
but sprouts from the stump are growing), 
and Columbus. 
‘Labels for Living Plants’ were likewise 
discussed by Dr. Kellerman. He exhibited 
a modified form of the printed label for liv- 
ing plants, already described before the Bo- 
tanical Club. In these he uses a printed 
card label in metal holder covered by mica 
sheets of proper size. This label in suitable 
sizes is adapted to use in the greenhouse or 
out-of-doors. 
. Under the title ‘The Introduced Species 
of Lactuca in Ohio,’ A. D. Selby spoke 
of the recent discovery of plants of 
Lactuca saligna L., south of Dayton; this 
was first collected in 1898. This species 
has been studied during a second season 
and is clearly a distinct. species from the 
pinnatifid-leaved forms of LZ. Scariola L. 
It is characterized by the slender, twiggy 
growth, the absence of spines and other 
minute characters. Photographs were 
shown to the club. This is seemingly the 
first recorded occurrence of Lactuca saligna 
in the United States. It seems liable to be- 
come widely dispersed. 
The same author spoke of some peculiar- 
ities of the yearly reappearance of Plasmop- 
ara Cubensis (B. & C.). This happens in 
Ohio, usually August 12th to 20th, not 
earlier, though possibly later the present 
year. The explanation of this phenomenon 
was asked; it seems peculiar in the absence 
of known oospores. 
“What shall we regard as Generic 
Types?’ was discussed by Dr. L. M. Under- 
wood. He reviewed, in the light of his 
work on the ferns, the method of residues as 
applied to inclusive genera when they are 
separated. Another method was suggested, 
[N.S. Vou. X. No. 246. 
that of regarding the first described species 
under the genera as the type of the genus. 
The Linnean or pre-Linnean genera 
must in this method be studied from their 
pre-Linnzan history. Professor Under- 
wood was inclined to support the latter 
method. 
After a discussion of the paper it was 
unanimously Resolved: ‘‘ That the question 
of the determination of generic types be 
referred to the Committee on Nomenclature, 
with the request that the Committee submit 
a report thereupon at the next meeting.” 
“A Brief Embryological Study of Lactuca 
Scariola Li.’ was presented by J. W. T. 
Duvel. This paper showed very briefly 
the development of the individual pollen 
grains from the chains of pollen mother 
cells. It likewise treated of the entrance 
of the pollen tube into the embryo sae, il- 
lustrating the ejection of the sperm nucleus 
and its union with the odspore; this union 
usually takes place near the center of the 
embryo sac, though such union may take 
place adjacent in the pollen tube. 
‘The Position of the Fungi in the Plant 
System’ was the subject of a paper com- 
municated by Professor H. L. Bolley. He 
submitted that the reported growth of bac- 
teria on a purely mineral medium would 
call in question the degenerate character of 
the group. But in his own work he had 
found that on cultures made by washing 
water-glass in running water and then in 
distilled water other fungi still flourished. 
Professor A. D. Hopkins presented some 
‘Botanical Notes by an Entomologist.’ He 
remarked upon the discriminating power of 
insects as between allied species of conifers, 
etc., and reported the occurrence of a Larix 
Swamp in West Virginia. 
Professor L. C. Corbett exhibited and il- 
lustrated the use of ‘A Device for Registering 
Plant Growth.’ This had developed from 
the author’s work a: Cornell University and 
in its completed form is a most satisfactory 
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