OLANDULAK SVSTEAI — UVSSAL GLAND. 
20 
III tho liniiiL-liiato species it is tpimd as a more or less (listiuctly 
localized origan, with projectiii”- folds or leaflets augmenting its 
secretory surface, and is 
placed between the rectum 
and the brauchia on the 
roof of the respiratory 
cavity, the gland being 
capable, on occasion, of 
pouring out an enormous 
ipiantity of mncns which 
escapes through the re- 
spiratory orifice. 
Fu.. (ill. — I)isseclion of / Vrv/ztrrt vk'ipara (L,) (after T 4-1 F) 1 x . j.1 
lleriiariJ), greatly enlargetl, sliowiiig the position of the tllG 1 UllllOllcXlGS tllG 
Ilypobranchial gland within the respiratory cavity, ami i t • x l* x* xl 
incidentally the arrangement of other pallial organs and IS llOt (llStlllCtly 
the innervation of the osphradinm. , i* i i i • i 
hr. hranchia, with leallets partially removed; ^^.d. ioCilllZCd illUl tllG GpltllG- 
gcnilal iliict ; hypohrancliial gland ; c;. osphradiuin ; i- i i i i n i 
r. rectum. Iml ^iaiKUilar ecllnlGS arc 
distributed over the walls of the respiratory cavity. 
'I'lie celebrated Imiierial or Tyrian imrple of the ancients was a 
jiroduct of the hjqiohranchial gland of species of Mnre.r, heaps cf 
whose broken shells may still be 
seen upon the Tyrian .shores. 
The secretion, though colonr- 
lo.ss when discharged from the 
gland, becomes more or less 
brilliantly coloured in correla- 
tion with the intensit}'’ of the 
light to which it is subjected, 
pa.ssing through an intermediate 
and definite .series of colour changes and emitting an nnplea.sant 
odour during the iiroce.ss. 
The Byssal (Jland, though the homologne of the ventral gland of 
the (iastroi)oda, is yet a characteristic peculiarity of the more 
sedentary Ikdecypods, enabling them to securely maintain jiosses.sion 
of any suitable station they ma)" have .selected as a permanent abode. 
'I’he byssal gland opens niion the median line of the hinder surface 
of the foot and consists of a byssal cavity with longitudinally jdaited 
walls and numerous divergent ramifying channels, from which emanate 
the chitinous fluid which is secreted jiartially by their epithial walls 
and partly by the glandular cells imbedded in the tissues, whose 
Fjg. 012. — Transverse highly magnified section 
through the Hypobranchial gland or mucous rib of 
/ "n'iparn vhdpnra (L.) (aflei ilernard), showing 
its character and close relationship to the hranchia 
and the subjacent blood sinus. 
hr. branchial filament in section, showing venous 
connection with h.s, blood sinus; hypo- 
branchial gland or mucous rib. 
