ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 311 



Sipunculid. The alleged hsematolytic function of the posterior part of 

 the ventral tube is an error of interpretation ; the lymphogenic function 

 of the interior part of the dorsal canal was recognised by the author 

 before Ladreyt had published his paper ;* the alleged excretory function 

 of the posterior part of the gland is a mistaken inference from the 

 presence of uric acid ; one might as well say that all the organs of 

 Selachians are excretory because they contain abundant urea. 



Abnormality in Genital Organs of Leech.| — Jules Bourquin describes 

 an abnormal doubling of the female genital organs of Hirudo medicinalis. 

 Each part consists of a vagina, an oviduct, and a single ovary. The 

 more anterior of the two opens as usual between the 29th and 30th ring, 

 and its missing right ovary has its place taken by a spiral canal which 

 runs into contact, if not into connection, with the right vas deferens. 

 The posterior organ — opening between the 34th and 35th rings — has 

 been pushed to the right by the first testis on the left side, and the 

 corresponding first testis on the right side is missing. 



Digestion in the Leech 4 — C. Spiess discusses the role of the pig- 

 mented cells found surrounding the digestive tract in Hirudo medicinalis. 

 Moquin-Tandon spoke of them as " hepatic tissue ;" others have shown 

 that they play an active part in the elimination of products of dis- 

 assimilation. Spiess points out that the cells in question are not derived 

 from the mesenteron, and do not morphologically correspond to a begin- 

 ning of a hepatic gland. They correspond rather to a kidney, but they 

 fulfil as such part of the functions which in Vertebrates fall to the hepatic 

 cells. The biliary pigments found in the leech are due to the haeniatin 

 of the blood which has been ingested. 



Systematic Relations of Chaetognatha. § — Paul Abric discusses 

 different types of Chaetognatha, witb especial reference to the fins. In 

 Scottochcdus, the system of fins (paired and caudal) is continuous ; in 

 Kroknochcetus, the continuity of paired fins with the unpaired fin is 

 broken ; in Lyrochwtus, the lateral fins are divided into two, and so on. 

 But these morphological series do not in any way represent the real 

 evolutionary series. " Morphological resemblances, however precise they 

 may be, ought not to lead us to prejudge the question of phylogenetic 

 affinity." 



Nematohelminthes. 



Family Mermithidse. || — E. Corti discusses Paramermis contorta 

 Kohn, and proposes the following division of the family Mermithidae : 



„_„ „ Muscular 



SUB-FAMILY flelds 



Mermithinaa / Neomermis, v. Linst, 1904 . 2 



(cuticle with - Mermis, Duj., 1842 . . H 



crossed fibres) ( Paramermis, v. Linst, 1898 6 



Hydromermithinse ( Hydromermis, E. Corti. 1902 8 



(simple cuticle) "(Pseudomermis, De Man, 1903 ? 



* Arch. Zool. Exper., iii. (1905) Notes et Revue, No. 4, pp. ccxv-ccxxiii. 

 t Rev. Suisse Zool., xiv. (1906) pp. 47-9 (1 fig.). 

 t Arch. Sci. Phys. Nat., xx. (1905) pp. 592-4. 

 § Comptes Rendus, cxli. (1905) pp. 222-4. 

 || Zool. Auzeig., xxix. (1906) pp. 627-31. 



