Miscellaneous* 323 



On the Respiratory Apparatus of the Ampullaria3. 

 By M. A. Sabatier. 



la a note inserted in the ' Comptes Rendus ' of the 12th of May 

 last, M. Jourdain described the arrangement of the respiratory ap- 

 paratus of the Ampullarice. Having already occupied myself with 

 this subject in 1877*, and having pursued my researches, I am able 

 to make known some new facts which had escaped the observations 

 of my predecessors. 



The venous blood, returning from the different parts of the body, 

 divides into three parts : — 1, one passes to the right into a cavern- 

 ous sinus, which accompanies the terminal intestine ; this is the 

 rectal sinus, which is a diverticulum of the general cavity of the 

 body : 2, the second part comes from the anterior region of the body 

 (head, pharynx, stomach, anterior margin of the palatine arch) and 

 forms on the right the proper afferent vessel of the lung, which it 

 circumscribes to the left and in front ; this vessel presents a double 

 series of orifices for the afferent branches of the roof and of the 

 floor of tho pulmonary chamber : 3, the third part, which is far 

 more important, comes together in a large deep vessel with muscular 

 walls, which soon ramifies on the lower surface and in the thick- 

 ness of the large gland, to which I have already alluded. From 

 this network the efferent vessels take their origin, the greater part 

 of which reunite in a large trunk with muscular walls which carries 

 the blood to the renal organ : this is the deep afferent vessel of the 

 renal organ, which is peculiar to the Amputtarice. The other vessels 

 which originate from the large gland discharge themselves succes- 

 sively into a superficial vessel of no great size placed on the posterior 

 margin of the renal organ, and which is its superficial afferent vessel, 

 corresponding, in all respects, to the single afferent vessel of the 

 other Pectinibranchiata. Hence the blood which has traversed the 

 large gland in a true portal system is not, as M. Jourdain thinks, 

 mingled with the blood returning from the organs of respiration, to 

 be immediate];/ poured into tho heart, but it does not reach this 

 latter organ until after it has traversed the renal organ first and 

 the respiratory organs afterwards. 



From the anterior margin of the renal organ there originates, by 

 successive roots, an effei"ent vessel of the renal organ, which, after 

 having anastomosed with the afferent vessel of the same organ, con- 

 tinues forward on the right margin of the principal branchia, of 

 which it constitutes the afferent vessel. This vessel receives, in 

 passing, some affluents proceeding from the rectal sinus. 



On the left margin of the branchia, between this latter and the 

 lung, is a large trunk which terminates at the auricle, and which is 

 not simply, as M. Jourdain thinks, an efferent vessel of the branchia 

 and of the lung. This vessel contains, in fact, a series of fissure-like 

 orifices, which pour into it the blood from the branchia, and two 



* Assoc, francaise pour favanc. des Sciences, session du Havre, 1877, 

 p. 623. 



