rs Mi 
them transparent. In Beath the stomata become visible fast if 
the zuardcells alone contain Anylon, while in others, when the 
clorophyll in a11 cells contains starch,this does no good but 
causes damage. The most difficult part of an investigation is 
always the preparation of useable crosscuts through the leaf to 
obtain certainty about the presence or absence „ the number and 
strength ofitne peripheral vascular bundles. In many cases the 
compressed tissue will not spreadput, not even when kikalrzd the 
cuts are boiled and alcali is used. IlIoften tortured myself all 
of 3 days to obtain certainty just about one species. With 1i- 
vine material however that is easy, if only the sections are 
made fine enouseh. FinallyI remark, that besides the amerlcans 
I have investirated many others,e.ge. africans from W.Wolwitch, 
2 southamericans from Spruce besides others, 
Your letter of January 8 I received 8 days ago and spent 
3 full days in examining the 2 califonians.These are really 2 
species ‚not one. I was most eager for the Iseetes from Cali- 
fornia; I expected something with a relation to the Isoetes of 
the southamerican Andean chain,, and actually here come two spe- 
cies with closest relationship to I.lacustus and echinospora. 
I’ californica, the name which may remain for the larger 
species,looks Infaot so similar to certain forms of Il,echinro - 
spora, that I would have taken it for this without knowledge of 
the the place of oririne. The same auick rejuvenation of the 
leaves, the same I AM of the tissue,but: The leaves covered 
heavily with stomata ! One can see them most by slicing the leaves 
in half and using a little tincture of iodine to color the starch 
in the guardcells. No vascular bundles. Velum covering 1/3 -1/2. 
The spores totally different from those of echinospora,covered 
with low,very weak,much twisted anastomic rootlets.The other spe- 
9 10 MISSOURI 
BOTANICAL 
eloJe)igtelsimg-ti-ie te GARDEN 
