Page:An introduction to physiological and systematical botany (1st edition).djvu/374

 344, the Sweet Pea of our gardens, a native of a very hot climate, at the summits of whose flower-stalks are generally found the rudiments of one or more flowers, not attempted to be perfected. So also the first Barley sown on the sandy heaths of Norfolk, and indeed too many a following crop, bears very few grains in an ear; for the same meagre supply of nourishment, bestowed equally on a numerous spike of blossoms, would infallibly starve them all. In like manner one seed only is perfected in the best wild Arabian Coffee, known by its round form; while the West Indian plantation Coffee has two in each berry, both consequently flattened on one side. The former grows in barren open places, in situations sufficiently favourable for the impregnation of its blossoms, but far less so for the perfecting of much seed; while the latter, well supplied with manure and moisture, is enabled to bring every germ to maturity.

Very strange effects are often produced upon plants by the attacks of insects, whence the various kinds of Galls derive their origin. These are occasioned by the punctures of