42 THE MICROSCOPE. 
BREWERIA PICKERINGII, GRAY. 
(Bonamia Pickeringii, Gray.) 
The pollen Brains of this rare plant, rare at least in New Jersey, 
are sub-spherical, ;1, inch in diameter, and entirely and minutely 
hispidulous, the surface growth measuring only about ;3';5 inch in 
depth. 
The specimen from which the pollen was taken I owe to the 
kindness of Mr. Isaac C. Martindale, an accomplished botanist, of 
Camden, New Jersey. 
CUSCUTA GRONOVII, WILLD. (DODDER). 
The pollen grains of this very common parasite are oval in out- 
line, measuring ;}, inch in length, by ;;';; in width, the entire sur- 
face being hispidulous. 
According to Gray’s “‘ Manual”? there are eight genera forming 
the Convolvulacese : Quamoclit, Ipomea, Convolvulus, Calystegia, 
Bonamia, Evolvulus, Dichondra, and Cuscuta. In his “ Synoptieal 
Flora of North America,” he recognizes eight, but makes some inter- 
‘eating changes. (Juamoclit, Batatas, and Pharbitis ( the two latter 
not being in the Manual), are merged in Ipomea ; Calystegia 
becomes Convolvulus; Bonamia becomes Breweria; and Jacque- 
montia and Cressa are added, while the remaining genera are 
unchanged. When I began to examine the pollen of the group, after 
having become so interested in that of the “ moon-flower,” I hoped 
to be able to see that of at least one species of each genus forming 
the order, excepting, of course, the genus Cressa, of which the only 
_ American variety is found “‘on or near the sea-shore or in saline soil, 
‘California, and from Arizona to S. Texas ( Hawaian Islands, S. 
America, &c.).” Although my correspondents have been kind and 
generous, Dichondra and Evolvulus are also missing. If the micro- 
scopists in the South and West where the species of these genera 
grow, will examine their pollen, it may be followed by interesting 
results ; it will at least be a satisfaction. The pollen grains need 
only to be dried and mounted in Canada balsam. The observer may 
be sufficiently skillful in the use of the microtome to section the 
grains, in which case still better results will be obtained. 
EXPLANATION OF THE PLATE. 
Fig. 1, Pollen of Ipomea Bona-nox. 
Gay ane een 4 as Portion of a transverse 
section ; 4, extinai papilla; B, extinal fringe; c, intinal papilla ; p, 
extine; E, intine; Fr, protoplasm, coagulated and withdrawn from 
the intinal papillee. 
