1 84 GLOSSARY. 



Sclerenchyma (a hard infusion). A tissue belonging to the 

 fundamental system and composed of cells that are thick- 

 walled, often excessively so. 



Scutellum (a small dish). The disk-like or shield-like cotyledon 

 of grasses. 



Seed. The matured ovule. 



Sepal. A calyx-leaf. 



Seta, pi. setae. A bristle, or bristle-shaped body; in mosses, 

 the stalk of the capsule. 



Sexual spore. One formed by the union of cells. 



Sheath. A thin enveloping part, as of a filament, leaf, or 

 resin-duct. 



Sieve-cells. Cells belonging to the phloem, and characterized 

 by the presence of circumscribed and perforated panels 

 in the walls; the panels are sieve-plates, and the perfora- 

 tions sieve-pores. 



Sorus, pi. sori (a heap). In ferns, the groups of sporangia, 

 constituting the so-called "fruit-dots"; in parasitic Fungi 

 well-defined groups of spores, breaking through the epider- 

 mis of the host. 



Sperm, or Spermatozoid (animal-like sperm). The male 

 gamete. 



Spermatophytes (seed-plants). The highest great group of 

 plants, of which a characteristic structure is the seed. 



Spike (an ear of corn). A flower-cluster, having its flowers ses- 

 sile on an elongated axis. 



Spikelet (diminutive of spike). A secondary spike; in grasses, 

 the ultimate flower-cluster, consisting of one or more 

 flowers subtended by a common pair of glumes. 



Sporangium, pi. sporangia (spore- vessel). The spore-produc- 

 ing structure. 



Spore (seed). Originally used as the analogue of seed in 

 flowerles plants; now applied to any one-celled or few- 

 celled body which is separated from the parent for the 

 purpose of reproduction, whether sexually or asexually 

 produced; the different methods of its production are 

 indicated by suitable prefixes. 



Sporogonium, pi. sporogonia (spore-offspring). The whole 

 structure of the spore-bearing stage of Bryophytes. 



Sporophyll. A leaf that bears sporangia. 



Sporophyte (spore-plant). The asexual or spore-producin , 

 stage of an alternating plant. 



