STILOPHORA. 



[ 618 ] 



STOMACH. 



BiBL. Berk. Brit. Flor. ii. pt. 2. p. 330, 

 Ann. Nat. Hist. vi. p. 432. pi. 12, ibid. 2iid 

 ser. V. p. 465; Fries, Summa Veget. p. 469. 



STILOPHORA, J. Ag.— A genus of Spo- 

 rochnaeese (Fucoid Algse), included by some 

 authors among the Dictyotacea3. There are 

 two British species, S. rhizodes and S. Lyng- 

 byei, characterized by a branched, filiform, 

 at first solid, afterwards tubular frond, the 

 former 6 to 24", the latter 2 to 4" long, ari- 

 sing from a small naked disk. The fructifi- 

 cation consists of little wart-like bodies, 

 scattered all over the frond, composed of 

 tufts of moniliform filaments, at the bases 

 of which are attached either pyriform oospo- 

 ranges, or tubular, septate trichosporanges. 

 Thuret states that the specimens of S. rhi- 

 zodesfound a certain distance above low water 

 mark appear mostly to bear trichosporanges, 

 those always under water oosporanges, and 

 those in an intermediate position exhibit 

 both. The plants of the first kind are of 

 paler colour than those of the second. 



BiBL. Harvey, Brit. Mar. Alg. p. 39. 

 pi. 7 C ; Greville, Alg. Brit. pi. 6 ; Thuret, 

 Ann. des Sc. nat. 3 ser. xiv. p. 238. pi. 38. 



STING, OF Insects. — The well-known 

 sting of the female or so-called neuters of 

 Hymenopterous Insects, as the honey-bee, 

 the humble-bee, the hornet, the wasp, &c., 

 appears to the naked eye to be a single, 

 needle-like organ; but when examined under 

 the microscope, it is seen to consist of three 

 pieces, a short, stout, cylindrieo-conical 

 outer piece or sheath (PI. 27. fig. 14 a), 

 cleft throughout its length on the under 

 surface and obtuse at the end, within which 

 are partly contained two long elbowed setae 

 or lancets (PI. 27. fig. 15, one of them), 

 thickened and furnished with teeth directed 

 backwards near the end of one margin, the 

 other margin sharp and cutting. These 

 setse play within the sheath, being partially 

 protrusile and retractile, as is the sheath 

 itself. The poison-apparatus consists of two 

 glandular elongated sacs, either simple (PI. 

 27. fig. 14 e,/), or branched as ia the humble- 

 bee, &c., and terminating by one (fig. 14 d) 

 or two ducts, in a muscular reservoir (fig. 

 14 c), from which an excretory duct runs to 

 the base of the sheath of the sting:. 



The irritation produced by the sting of 

 one of these insects needs no remark. It 

 does not, however, serve a merely defensive 

 purpose, but is used also to paralyse the 

 prey, so that it may be kept in store for 

 future use. 



The sting represents a modified ovipositor. 



BiBL. Lacaze-Duthiers, A7in. d. Sc. nat. 

 3 ser. xii. xiv. ; Westwood, Introduction, 

 Si'C. ; Siebold, Vergl. Anat. 



STINGS, OF Plants. — These are epider- 

 mal structures, consisting of large Fig. 706. 

 hairs, with a bulbous base more or 

 less included in a cellular coat, and 

 attenuated upwards. In the sting 

 of the nettle the apex is expanded 

 into a little bulb, which is broken 

 off when the sting is lightly touched 

 (PI. 21. fig. 8).. Young stings ex- 

 hibit the Rotation. Stings occur 

 not only in the nettles ( Urtica), 

 but in the cultivated Loasaceae 

 {Loasa,Bartonia, &c.), and of much stinging 

 larger size in some exotic Urticaceae ^^i^" ^^ 

 and Euphorbiaceae. Magnified 



See Hairs, page 314. 2odiams. 



STOMACH.— The glands which secrete 

 the gastric juice are tubular glands, perpen- 

 dicularly placed beneath the svu-face of the 

 mucous membrane, and extending as deeply 

 as the muscular coat of the stomach. 



They vary in length from 1-60 to 1-12", 

 are cylindrical, somewhat narrowed towards 

 the closed end, which is rounded or some- 

 what inflated. The lower third is wavy or 



Fig. 707. 



ISlffiliiiliifi 





u 





€ 



d 



e 



f 



Fig. 707. Perpendicular section of the pyloric portion! 

 of the stomach of a pig. a, glands ; b, muscular layerl 

 of the proper mucous membrane ; c, submucous tissual 

 with the orifices of divided vessels ; d, transverse mus-J 

 cular layer ; e, longitudinal ditto ; /, serous coat. Mag- 

 nified 30 diameters. 



spiral, especially in the glands occupying tliej 



