Invcrtebrata. Zoological Collections, 906 



In many parts, such as the heart, diaphragm, the digestive and urinary 

 organs, what is held to be cellular tissue, entirely disappears after a success* 

 ful itijection of the absorbent vessels. 



The tissue by which the serous and mucous membranes are attached tor 

 the adjacent surfaces, and which is usually held to be cellular membrane, is 

 in fact nothing more than a vast multitude of absorbent vessels, and can 

 no longer be detected as an independent substance, after a successful 

 injection bf these vessels. 



2. The absorbent vessels do not arise, as many suppose, in the form of; 

 branches, which afterwards unite together to form larger trunks, but, at theic' 

 origin or termination in the substance of organs, form a plexus, or network,- 

 which is interwoven with the blood-vessels, and, in membranous parts^ 

 extends nearer to the surface than blood-vessels, so that it constitutes the 

 most superficial layer of the skin, and of serous and mucous membranes. 

 In such situations, the network becomes extremely tine, and so close, that 

 it is impossible to insert a pin's point without wounding an absorbent vessel* 



3. The absorbents do not commence with open mouths, at least not with;- 

 orifices such as the puncta lachrymalia, or as Lieberkuhn imagined he had ■ 

 observed in the intestines. They are not furnished with separate inhaling- ? 

 radicles, but the vessels which enter into the formation of the network 

 absorb through their ])arietes. Whether these are perforated with special 

 inhaling orifices, cannot yet be decided with perfect certainty. Professor - 

 Fobmann has never seen any such, and is therefore of opinion, that if th€ry' 

 really exist, they are of such a nature as not to be perceptible by the senses. 

 •"-his. 



Four-spined Stickleback A variety of the stickleback, (GasterosteitS 



aculeatus,) with four spines on the back, was discovered in a pond in the 

 Meadows, by Mr John Stark, in September, 1830. The common three- -i 

 spined stickleback was numerous in the same pond ; and, of a number taken • 

 in a net at random, about one in ten or twelve proved to be of the four- 

 spined variety. This variety (or, perhaps, species) does not appear to have 

 been previously noticed. It is somewhat smaller than the common three- 

 spined stickleback when full grown, the specimens prociu-ed not exceeding 

 one-fourth of an inch in length. The arrangement of the spines is also^ 

 different, being placed in twos, at regular distances, corresponding to the 

 length of the spines. The two anterior spines are much longer than the 

 other two ; the second longest Stark, in Edin. New Phil. Jour. Mar. 1830. 



ei oii-jyg ^ 



New Genus of Marine Worms, (Notospermus ;) described and figured by 

 M. Huschke. — The author found two individuals of this genus on the coasts 

 of Sicily, near Trapani, among the stalks of the officinal coralline. Both 

 were from three to four inches long, by about two lines broad. "When alive, 

 they were slightly flat, but in alcohol they became strongly contracted, and 

 assumed a cylindrical form. This worm, whose body has neither rings nor 

 appendages, is quite smooth, and externally presents nothing particular but 

 its colours. It crawls like the snail ; although sometimes, vv'hen in water, 

 it exhibits undulatory motions. 



The animal has about sixteen green bands surrounding its body, each of 

 which is nearly two lines in breadth. These bands are separated from one 

 another by white bands, which are narrower. The two green bands, which 

 are the most anterior, surround the head : the head is flat near its extremity, 

 where there is an orifice by which a tentaculum, supposed by M. Huschke' 

 to be the male organ of generation, is protruded. The mouth opens below, 

 in the second green band; it has the form of an elongnted fissure, the 

 circumference of which is coloured red. The anus is at the posterior 



VOL. III. 2q 



