378 BOTANICAL GAZETTE [MAY 
Cutleria is a delicate little plant of the Phzozoosporee, that commonly 
grows in quiet water at a depth of at least two fathoms below tide mark, and 
vegetates at a mean temperature of 16°. It is widely distributed along the 
coast of Europe and in the Mediterranean, but is a seasonal form, being quite 
sensitive to changes of temperature. Thus at Plymouth, England, it is a 
summer annual which disappears in October. Cutleria bears sexual organs 
that discharge biciliated gametes of two sizes which have been observed to 
conjugate, the smaller with the larger. But the sexuality apparently depends 
upon a narrow range of physical conditions, and when these conditions are 
not present the plant is parthenogenetic. Thus, although the process of fer- 
tilization has been observed at Naples by two investigators, Reinke and 
Falkenberg, parthenogenesis is known to be extensively present among these 
plants in the English Channel at the end of the summer. Perhaps the par- 
thenogenesis is associated with a fall in temperature. Extensive experiments 
by various observers have proved that the oospheres of Cutleria, whether 
fertilized or developing parthenogenetically, produce young plants with 
undoubted Aglaozonia characters. 
Aglaozonia is a perennial on the English coast, much coarser in histology 
and stronger constitutionally than Cutleria, for it can stand a range of tem- 
perature from less than 3° to more than 20°. It also grows in far more 
exposed situations than the latter plant. Church has been able to raise young 
plants from the zoospores of Aglaozonia, and these developed protonema-like 
creeping filaments that finally matured Cutleria antheridia. These may be 
regarded as “ precociously developed”? male plants. Thus experiment has 
connected back and forth into one life history the forms formerly known as 
Cutleria and Aglaozonia. 
It is well to bear in mind how unsettled are the data in respect to sexual- 
ity among the Phaozoosporee at the present time. ctocarpus siliculoses ® 
one of the classical forms in which sexuality among these alg@ ws 
announced. But Kuckuck believes that this species is constantly partheno- 
genetic at Kiel, and Reinhart has observed both the conjugation and direct 
germination of gametes. And again, extensive studies by Sauvageat a 
several species of Ectocarpus indicate that motile cells usually consider 
gametes germinate without difficulty --BRADLEY MOORE Davis. 
