1896, ] briefer Articies. 235 
Ruamnus Francuta L., Sp. Pl. 193. 1753.—Mr. W. M. Van Sickle, 
of West New York, N. J., reports the discovery of additional speci- 
mens of this interesting European buckthorn in the swamp at Secau- 
cus, some distance from the present known locality at New Durham. 
The problem concerning its mode of introduction into the United 
States is a difficult one to solve. The fact of Michaux’s Arboretum 
having been situated on the site of the present New Durham swamp 
indicates that it may have been originally planted there, an d thriving 
under favorable conditions, spread rapidly and in time developed 
trees of the size now found. It was long age rep »rted from Flushing, 
Long Island, but this station is now apparently obliterated.—CHARLES 
Louis PoLiarp, Washington, D. C. 
Pebble mimicry in Philippine island beans.—In looking over a keg 
of pebbles collected from the coast of Marinduque by Dr. Joseph B. 
Steere in his expedition of 1887-8, some beans were found which sur- 
prisingly resemble the water-worn pebbles with which they were asso- 
ciated. The mimicry is so perfect that almost every one is deceived 
tntil an opportunity for handling thein is afforded, and even after be- 
Ig made aware of their nature mistakes will still occur. Inquiry devel- 
oped the fact that these beans are produced bya coarse briar le 
was expected, to the narrow strip of gravelly beach and met with 
here and there upon various members of this group of islands. Send- 
Ing out trailing stems to a distance of twenty to thirty feet, carrying a 
leaf similar to that of the rose, they form a mat from three to four 
“tin height quite difficult to penetrate. Di Se ee 
tives collecti ng them for shipment to Manila, to be used, as they said, 
I the Manufacture of soap. 
The beans, themselves, are sub-ellipsoidal in form, but show much 
Megularity “ shape, apparently from mutual pressure in the pod. 
€ 
= Tounded by continued friction. A handful of the beans shows 
much and the same character of variation as is seen in the same 
sage of quartz pebbles. The size is as variable as the shape, 2 
ba “imensions ranging in different specimens studied from oo 
Nee typical specimen being about 17X18 14" The co 
ite tinge, while the luster of many is exactly t at oh. 
tained . Others of lighter color the effect is similar to pte 
all th "om pebbles of chalcedony or of crystallized quartz. y eee 
© Specimens show a series of approximately paralle 
