20 
the science ; but this field has been so well worked, and is so full 
of workers, that there is little room for any new comer to add 
much to our knowledge in this department, while the other 
divisions of the science offer unlimited range for delightful and 
profitable investigation. Whether taking his healthful walk in the 
country after rarer plants, or confined to the weeds of his door- 
ard, the student of vegetable biology can always find subjects of 
interest. If a few more of our able investigators would disclose 
to outsiders their methods of research, so as to set the current of 
study in that direction, they would be doing good service. We 
heartily thank Prof. Biscoe for his example of honestly thorough 
work in a somewhat neglected field. 
§ 29. Publications—The Naturalist for May is unusually well 
supplied with botanical matter. Prof. Biscoe’s article on Duck- 
weed we have elsewhere noticed. Prof. Watson describes some 
new plants of Arizona.—WSilliman’s Journal contains, with other 
notes of interest, obituary notices of Curtis, Mohl, and others. A 
biographical sketch ot Dr. Torrey is promised for the June num- 
ber.—Archives of Science, Vol. I., No. 6, continues the list of 
flowering plants of Vermont, by Prof. Perkins, and of the Crypto- 
gams, by Charles C. Frost.—The Popular Science Monthly for May 
has an interesting article on the freezing of plants and animals, from 
the German of Fr. Mohr.—In the Transactions of the Wisconsin 
Academy, 1870-72, Dr. Lapham discusses the classification of 
plants in the light of Geology. 
§ 30. Motion of Fovillz ( Pollen contents).—We extract the follow- 
ing paragraph from the note of a friend: “I was recently examining 
the pollen of the common Calla, so called, (Richardia Aithiopica). 
The granules are unusually large, and are admirable for study in 
‘several respects. ‘They show, with unusual distinctness, the double 
character of the coat. he foville shrink away to the centre, 
leaving the margin all around the granule transparent. I had 
placed some of the pollen upon the slide with a drop of water. 
Soon I found some of the granules burst, and the contents poured 
out like meal from a sack. But in a moment it was ‘all alive.’ 
Each particle of the foville went whirling around and twisting 
away, now on its own hook, now bowing to its neighbor, and aggre- 
gating with others similar. The whole field was covered with a 
cloud of busy particles, moving about with « sort of infusorial 
motion, but much slower. This lasted for an hour or two. If the 
granules do not burst by the absorption of water, they may be 
crushed in the compressorium, or simply with a knife-blade or sim- 
ilar instrument.” 
Terms— One dollar for one copy ; five dollars for seven ; and half a dollar Tor every additional 
copy per annum. 
Local Herbarium, 3, E. 33d St.—Editor, 224, E. 10th St. 
_ The Ohi meets regularly the last Tuesday of the month in the Herbarium, Columbia College, ae 
