Life-history of Tetraclinis articulata. 585 
namely, that some are straight and some bent into a V-shape. If we 
assume, as would appear to be the case, that the chromosomes have split 
after passing away from the equator, as in many other plants, then the 
twenty-four would be accounted for if sixteen of them were straight and 
the other eight V-shaped. I can suggest no other explanation which 
appears in any way satisfactory, and which is at the same time not contrary 
to all accepted views in regard to chromosome numbers as seen during the 
meiotic phase. 
Nichols ( 36 ) maintains that after synapsis there are no parts of the 
spireme which meet and fuse, that is, no anastomosing; the spireme is one 
continuous thread. Noren, on the contrary, considers that anastomoses do 
occur, as is also said to be the case in Pinus (Ferguson ( 17 )). In Tetraclinis 
there is no doubt whatever that anastomoses do occur in the post-synaptic 
spireme. They are most clearly seen where only a small part of the nucleus 
is cut off in a section ; in thicker sections it is difficult to distinguish clearly 
between a real branching (anastomosing) of the thread, and the case where 
one part of the thread crosses just below or above another part. At the 
same time it is evident that there is much less anastomosing after synapsis 
than there was before. 
The only other point worthy of special mention is the complete absence 
of any trace of fibres prior to the cleavage of the contents of the mother-cell 
into spores. In Juniperus , Nichols ( 36 ) gives a figure showing more con- 
spicuous fibres at this time than at any other stage of the meiotic divisions, 
and they have been described and figured in most other cases where this 
phase has been investigated. As their absence here appears a distinctly 
unusual feature, it may be worth mentioning that the regular arrangement 
of the starch grains almost entirely precludes the possibility of such fibres 
being present, even on the supposition that the methods of fixing and 
staining were not sufficiently good to demonstrate them visibly in any one 
of the numerous preparations showing this stage ; as a matter of fact the 
fixing and staining appeared entirely satisfactory in many cases. A com- 
parison of Fig. 17 with Figs. 22 and 23 will explain what is meant in 
regard to the starch grains. In Fig. 17 these are arranged in rather 
definite rows, and are somewhat elongated in the direction of the fibres, 
as though compressed by the latter, while nothing of the kind is 
visible in any of the hundreds of cells examined in stages similar to 
Figs. 22 and 23. 
The Male Gametophyte. 
When pollination takes place the grains usually lodge on the edge of 
the crater-like apex of the nucellus, and the tube grows into the central 
collapsed area, and then turns downwards. The earliest stage seen after 
