182 MIMICRY IN NATURE. 
Carpinus Betulus. Luzula pilosa. 
*Larix Europea. (Fertile) os Poa annua. March 25. T. 
Buxus sempervirens. See ip "s Tulipa sylvestris. March 30. A. 
Mar | 1& JL 
| 
13. E.J.T. (Male) March 23. | 
. and 8. | 
MIMICRY IN NATURE. 
We have heard lately much about * Mimiery in Nature," where cer- 
tain features of one species reappear in another not in any way related 
to it, as, for instance, in the Pineapple, where the fruit bears a striking 
external resemblance to a Pine-cone ; certain spiny Euphorbias, where 
the stem has the look predominating in the Cactus tribe, or in the iron 
or beef-woods (Casuarinas), where the branches are singularly like our 
Horsetails, or Equisetums. On the Nicaraguan rivers I met several 
curious instances of this, viz. some plants belonging to what Humboldt 
has aptly termed the Willow form. There were genuine Willows, 
which the country-people termed ** Sauce,” the fresh green of which 
afforded a pleasing relief to the eye after gazing so long on dried-up 
or leafless vegetation; but with them grew not only the feathery 
Bamboo, and the beautiful Lindenia rivalis (both good instances of 
the Willow form), but also a yellow-flowering Bignoniacea (Astianthus 
longifolius, D. Don), often forty feet high, and a tall Composita, both 
known by the Quichuan name of “ Chilca,” which, unaffected by the 
periodieal rising of the water and the turbulence of the stream, not 
only had the same foliage, habit, and mode of growth as genuine 
Willows have, but served the same purposes in nature's economy, by 
protecting and keeping together the river banks. In the Viti Islands 
I observed similar instances of the predominance of the Willow form on 
rivers (Lindenia Vitiensis, Acalypha rivularis, Ficus bambusefolia, two 
species of Bamboos, etc.). The question then as now presented itself 
—what possible connection can there be between the two? Do these 
plants grow on rivers because they have Willow-leaves, or do they 
have Willow-leaves because they grow on rivers? This is, in fact, the 
old question over again—Does the duck swim because it has webbed 
feet, or has it webbed feet because it swims 2—‘ Doltings on the Road- 
side,’ B. Seemann, p. 46. 
