328 BOTANICAL GAZETTE [APRIL 
of an analysis of the earlier treatment of plant formations or associations; 
Professor Henslow concludes, after an employment of the expressions 
“mimicry” and “ mimetic,’ which is rather different from that usual with 
naturalists, that ‘natural selection is quite uncalled for, and, in fact, has no 
raison d'étre in the origin of any structure whatever;” and Mr. Bulman 
reaches the conclusion that the theory of the origin of flowers by the selec- 
tive action of insects, ‘as taught by Darwin, Wallace, Hermann Miller, Sir 
John Lubbock, and Mr. Grant Allen, is absolutely incompatible with the facts 
of the mutual relations of insects and flowers.” —W. T. 
IN A PAPER® reviewed in an earlier number of this journal,’ Oltmanns 
claimed to have disproved the earlier work of Berthold,’ according to which, 
‘in Ectocarpus siliculosus, a quiescent female gamete becomes attached to 
several male gametes, with which it is said to fuse. Basing his conclusions 
upon a study of £. criniger, Oltmanns claimed that Berthold saw, not fusing 
gametes, but infusoria capturing and eating the algal zoospores. Berthold 
replied immmediately,? insisting that his preparations were not susceptible of 
any interpretation other than the one he had already given. 
Recent work by Oltmanns® upon &. séZiculosus has led him to abandon 
his former position, and to confirm the statements of Berthold. He ind 
finds infusoria, as before, but he also finds gametes fusing, and described the 
process quite fully. 
Several male garnetes become attached to the female by their long ante 
rior Cilia ; finally one is drawn nearer, and fusion follows. In material Col 
lected in the morning this generally occurs before noon, and nuclear we is 
usually completed before night. The fusion of the female with more bg 
one male gamete is very rare, but ‘the author does not tell us of the fate f 
the second male nucleus when this occurs. The second chromatospheré ® 
the normal zygote is said to persist. 
We may then say that the Ecocapaceze show se sHicult- 
stages of transition from i isogamy, through such forms as Ectocarpus st sen 
Sus, in which there is hardly more than a physiological citer to 
gametes, to the distinct heterogamy of £. wed oe in which, accor : 
Sauvageau, the two gametes differ considerably in siz 
The “neutral” swarm- -spores which are almost Sea ” 
gametes in the plurilocular sporangia, arise secondarily by the 
fusion, and therefore do not stand in a close phylogenetic ee 
Swarm-spores of the unilocular sporangia.—W. D. MERRELL. 
xual conditions in all 
ociated with the 
failure of gexual 
on to the 
° Flora 83 : 398-414. 1887, 7 Bor. Gaz. 24 1 383-384 1897: 
*Mittheil. d. zool. Stat, Neapel 2: 401. 1881. 
* Flora 83 : 415-425. 1897. 
* Ueber die Sexualitat der Ectocarpeen. Flora 86 : 86-99- 1899. 
