592 ORGANS OF SECRETION. 



which it suspends itelf and its spawned ova at the surface of 

 the sea, is formed by a glutinous secretion of the mantle, 

 enclosing globules of air. 



The small swimming pteropods, both naked and testaceous, 

 are, at least, provided with distinct chylopoietic glands. In 

 the clio and the pneumodermon, single long salivary tubuli 

 open into each side of the buccal cavity, and numerous hepatic 

 lobes, composed of compact clusters of biliary follicles, and 

 enveloping a large part of the intestine, open freely by short 

 separate ducts into the cavity of the stomach. The liver of 

 hyalea likewise consists of small aggregated biliary follicles, 

 forming a compact lobulated mass investing the intestine, as 

 in most inferior mollusca, before opening into the stomach. 

 And the genital glands, both oviferous and seminiferous, 

 have still the simplest follicular structure of isolated tubuli, 

 or of a few racemose groups of small follicles, the ovary being, 

 as usual, the more complex gland. 



The secreting organs of the cephalopoda approach nearer 

 to the vertebrated type in their form, structure, and con- 

 nections, than those of all the inferior invertebrata. Their 

 diminished cutaneous mucous secretion is a further affinity 

 with higher tribes, and is compensated for by the copious se- 

 cretion of muciparous follicles in every part of the digestive 

 apparatus, as well as by the higher development of all the 

 normal chylopoietic glands. Two large pairs of lobed salivary 

 glands, analogous to the parotid and submaxillary, consisting 

 of aggregated lobules of small white dilated follicles filled 

 with their salivary secretion, open by lengthened ducts 

 into the back part of the buccal cavity, and correspond with 

 the sharp and powerful cutting maxillae, and the numerous 

 recurved lingual teeth of these predaceous, though generally 

 naked, mollusca. In the great size and the conglomerate 

 character of the liver, and in its opening by a single length- 

 ened duct near the pylorus, they indicate affinities to the 

 fishes as well as to the lower mollusca. The short dilated 

 parallel tubuli biliferi, filled with their brownish-yellow 

 secretion, and directed with their shut ends towards the 

 entire periphery of the organ, and of its component lobes, 

 are easily seen with the naked eye, by removing carefully 

 the thin, soft, investing peritoneum, and then floating a 

 small piece of the liver in water. The pancreas here presents 



