630 Timber lake. — Starch- Formation in 
the starch or the pyrenoid should wholly disappear before the 
spores are formed ; for, as Klebs observed, and as many of my 
preparations show, in spores just formed, as well as during 
cleavage-stages, an abundance of starch may be seen, always 
appearing as if in a stage of solution (Fig. 27). Pyrenoids 
may also be present at these stages. Klebs thought the starch 
to be what he called the stroma-starch, as he failed to see the 
remaining pyrenoids here and there through the segmenting 
protoplasm, and even in some of the swarm-spores (Fig. 2 8). 
In such pyrenoids, however, I have never seen any indication 
of starch-formation. My preparations seem to show that the 
formation of starch has ceased, but that conditions were such 
that cleavage took place without the preliminary solution of 
the starch as well as the body of the pyrenoids. The relation 
of the pyrenoids and starch to spore-formation I hope to dis- 
cuss more fully in connexion with an account, now in prepara- 
tion, of the spore-formation. It should be especially noted 
that the presence of starch-grains in the young spores that 
contain no pyrenoids does not mean the formation of such 
grains in situ , but that they are grains of starch formed in the 
manner previously described, and simply remaining in the 
portion of the protoplasm forming the spore. In this con- 
nexion it may be further noted that under certain conditions 
the pyrenoid itself may entirely disappear, leaving the surround- 
ing starch-layer or layers still intact (Figs. 19 and 30). This 
condition seems to arise in cells in which there is no sign of 
cleavage to be found, but it is possible that it may also occur 
just prior to cleavage, so that all the swarm-spores formed in 
any one cell may contain starch, but none of them show a 
pyrenoid. It should be borne in mind that, as Klebs has 
pointed out, prior to cleavage the number of nuclei in the 
mother-cell is far in excess of the number of pyrenoids, so 
that even should the pyrenoids persist during cleavage, as 
they in some cases do, many of the uninucleate spores would 
be without them, a fact that seems to point unmistakably to 
the de novo origin of pyrenoids in the young cells. 
During the solution of starch around the pyrenoids there is 
