68 BOTANICAL GAZETTE [juLY 
F, A. WAUGH (Vt. no. 67, pp. 30) discusses hybridity among cultivated plums, 
and gives a systematic account of hybrid forms. Interesting trees of Vermont 
are described and figured by ANNA M. CLARK (Vt. no. 73, pp. 52), and those 
of Wyoming by AVEN NELSON (Wy. no. 40, pp. 52). W. W. ASHE (N.C. 
no. 175, pp. 8) gives technical diagnoses of 21 new species Crataegus and 
8 new species of Panicum, E.E, BOGUE publishes “An annotated catalogue 
of the ferns and flowering plants of Oklahoma” (Okla. no. 45, pp. 48), D. A. 
SAUNDERS does the same for South Dakota (S. D. no. 64, pp. 127), and 
Henry L. BoLiey and L. R. WALDRON do the same for North Dakota (N. 
D. no. 46, pp. 91), all excellent beginnings toward complete floras of the 
respective states. C. F. WHEELER writes about the dwarf mistletoe in 
Michigan, with good reproductions from photographs, and on other topics 
(Mich. no. 186). L.H. PAMMEL describes the horse nettle (Solanum Caro- 
linense), bind weed (Convolvulus arvensis), and ground burnut (77ridulus 
henite as troublesome weeds in Iowa (Ia. no. 42.) D. A. BRODIE (Wash. 
0. 45, pp. 12) gives facts establishing the poisonous nature of the Oregon 
seer nas (Cicuta vagans).—J. C. ARTHUR 
FERTILIZATION IN Ginkgo éiloba has recently been studied by Ikeno,” 
who gives a detailed account of phenomena from the cutting off of the ventral 
canal cell to the first division of the nucleus of the oospore. The nucleus of 
the ventral canal cell rapidly disorganizes, but in one instance it had enlarged 
part passu with the nucleus of the oosphere. In pr arations stained with 
methyl blue and acid fuchsin, the metaplasmic ground substance of the 
lar mass, also takes the red, while the nucleoli stain blue. e nucleus then 
undergoes a great change in structure, so that the metaplasm and chromatin 
can no longer be distinguished from each other. The further development 
of the nucleus of the oosphere agrees with the description of the correspond- 
ing phenomena in Pinus Laricio as described by the reviewer in 1899. e 
tube nucleus and the nucleus of the stalk cell disorganize within the pollen 
tube and do not enter the oosphere, and it is very probable that only one of 
the male cells is discharged, the other disorganizing without being able to 
enter. The nucleus of the male cell slips out from the cytoplasm mantle 
before fusing with the nucleus of the oosphere. The mode of fusion is like 
that already described for Cycas revoluta, that is, the male nucleus gradually 
penetrates the egg nucleus before losing its own membrane. At the time of 
fusion the sex nuclei are very unequal in size, the female being about ten 
times as large as the male. The behavior of the chromatin during fusion is 
not described. The spindle in the first division of the fusion nucleus is very 
broad and multipolar, and is never parallel with the longitudinal axis of the 
7°Contribution 4 l'étude de la Seinen chez le Ginkgo biloba, Ann. Sci. Nat. 
Bot. VIII. 13: 305-318. pls. 2-3. 
