BOTANICAL GAZETTE. 329 
mentary prothallium, because the vegetative cells (when more than one) are 
cut off successively from the progamous cell. T 
anthesis, the larger one is the vegetative and the smaller the generative cell, 
contrary to present nomenclature. It is found that there is in most cases a 
difference between the nuclei of these two cells in their capacity for taking up 
been thought to be 
division is characteristic of whole families, among which are mentioned the 
minew, Cyperacexe, Juncacer, Caryophyllacese, Umbellifere, ete. The veg 
etative nucleus never divides, notwithstanding such division has been claimed 
i e n th 
in sin keeps near the end of the tube and is prevented more or less com- 
pletely from returning to the empty part by plugs of cellulose, except a few 
i ases the 
cases, ually the vegetative nucleus goes ahead, yet 8 
aga one (or two) is t, and in other species s times one and sometimes 
' he generative nucleus in Angiosperms divides once at 
east, and usually so in Gymnosperms h of the nuclei thus produced do 
hot become destroyed, earlier negative results being due to imperfections in 
methods of researc e vegetative nucleus can be followed in monocotyle- 
reduction in 
ra It is ot erwise in dicotyledons. The veget : 
arlier or later in the pollen tube and only the twe generative 
ule. is point is an important one; it strongly suppo 
- rudimentary prothallium in Angiosperms, a concsus 
lin, doubt as to the small cell or cell-complex of Gymnosperms be 
Ph The author is somewhat inclined to consider the whole 
f anerogams and the microspores of vascular Cryptogams as 
of the antheridia. : : 
ti I. In studying the entrance of pollen tubes into the stigma several dis- 
a modes were observed. The first case is that in which (in species of Lilium) 
¢ pollen tube grows downward on the one-celled club-shaped papitie of the 
stigma, forces its way between their bases and enters one of the three narrow 
: Through this canal, adhering 
wall of of the outer ra of 
alr of the lini ity of the ovary. another 
- ven cells, they descend to the cavity © aba ae cali. 
selva re (thou E hes sometimes | “ oS elt 
etrate t ille cells , 
e the bases of the pa Malvaceee behave in the same way 28 
d . 
though est of the Caryophyllacez a with it. 
ee 4 tien ae w ‘penetrate the ‘epidermal cathe of the a 
a —- are not at all prolonged hardly even swollen) thongh the outer en 
ese celle is somewhat cutinized! “Lrhe pollen tubes] show in their 
