1895.] Briefer Articles. 81 
And while writing I will mention that two species of Picris still rare 
in America, have in their travels reached this place; P. Aieracioides and 
P. echioides have both been found this last season within our city limits, 
and also Alyssum incanum has appeared for the first time. Azol/a Car- 
oliniana has surprised us too, in our largest park, but as the pond 
which it covers with its fronds is full of lotus plants (Ve/wmdéo), it is 
pretty certain that it came in with their roots. It shows that it is not 
quite at home in our northern waters by being of slender growth and 
producing no fruit.—Maria L. OwEN, Springfield, Mass. 
Lencoplasts.—It may be of interest to some to know that first-class 
material for starch formers, showing all stages of the formation of 
coplasts, either clustered about the nucleus or scattered throughout 
the cytoplasm. For study it is only necessary to remove the dia- 
Phragm with a scalpel, pocket knife, or other similar instrument, 
mount and treat with reagent to suit the occasion. The lower eight 
to twelve inches of the petiole furnishes the best material. The botan- 
ical department of the University of Wisconsin can furnish a limited 
amount of this material to institutions not having access to the grow- 
ing banana plants, at the cost of transportation.—L. S. CHENnry, Uxi- 
versity of Wisconsin, Madison. 
Formule for life histories.—By an oversight the signs following S 
in the second, third, and fourth formulae printed on page 31 of the 
January number were o (representing gametes) instead of O (repre- 
senting spores). Readers should make the correction.—J. M. C. 
