YALE AGRICULTUEAL LECTURES. 109 



V. The kind of culture and the manures best adapted to 

 stimulate its growth and to increase its valuable properties. 



VI. The time of flowering of each species, and the time when 

 it ripens its seed. 



VII. The species of insects which prey upon it, and the best 

 modes of preventing their ravages. 



VIII. The best and most economical means of curing and 

 preserving each species of grass. 



To enable farmers to make these observations, they were ad 

 vised to study botany ; and the remainder of the lecture was 

 occupied in describing the parts of the grass which are mainly 

 resorted to in order to establish the distinctions of species. 

 Some of these descriptions are peculiarly valuable, because not 

 given in any work on botany which I can now recall. The 

 leaves consist of the following parts: (a) The Sheath^ which 

 represents the petiole or leaf-stalk of other plants ; (b) the Li- 

 gule, or tongue; (c) the Lamina, blade or flat part of the 

 leaf, that which in popular language is called the leaf, (a) 

 The sheath is the foot-stalk of the leaf. The whole length of 

 it, which is variable, is folded around the stalk (culm), from 

 which it can be loosened by unwinding, without fracture, a 

 circumstance which serves to distinguish the grasses from the 

 sedges, (b) The ligule, or tongue. At the point where the 

 sheath ends and the blade begins, occurs a thin and usually 

 white semi-transparent membrane, termed the ligule. As the 

 botanical works barely describe this, and still perplex us with 

 constant allusions to this and other parts of which we have 

 about as little knowledge as of the Choctaw alphabet, it is well 

 to remark that this ligule is said to be entire when it has no 

 segments; bifid when it is divided at the apex into two parts; 

 lacerated when it appears as if torn on the margin; ciliated 

 when the margin is set with short, projecting hairs ; truncated 

 when the upper part terminates in a transverse line ; acute when 

 it has a short, sharp point ; and accuminated when it has a long, 

 projecting point. It has great value in enabling us frequently 



