576 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and not in communication with the coelomic spaces. There are four 

 longitudinal main vessels — the aorta, the sub-intestinal vein, and two 

 cardinal veins. The sub- intestinal vein is purely splanchnic, the 

 cardinals purely somatic, the aorta both. The aorta gives off metameric 

 branches, which unite at their distal ends in longitudinal stems. The 

 aorca is double in the branchial region. The primary somatic branches 

 of the aorta are all on the median side of the trunk muscles. The 

 collaterals of the cardinal veins are on the outer or cutaneous side of 

 the muscles. The metameric arteries and veins form the subcutaneous 

 network, which subserves cutaneous respiration. The blood flows from 

 the sinus venosus into the endostylar artery, and then for the most part 

 on to the branchial region. Part of the blood passes into the terminal 

 twigs of the endostylar artery, which probably communicate with the 

 endostylar vein. Thence this quantum of the blood returns to the 

 sinus venosus. From the branchial region the blood passes to the carotids 

 which form the facials in front, the aorta behind. But we cannot do 

 more than indicate the detailed description which has now been given of 

 the circulation in the lance let. 



Brain of Amphioxus.* — H. C. Delsman discusses the development 

 and homology of the so-called brain of Amphioxus, and concludes that 

 it corresponds only to the posterior brain (deuterencephalon) of Craniota. 

 The neuropore of Ampliiowus does not correspond to the neuropore of 

 true Vertebrates. According to Delsman's view of the origin of Yerte- 

 brates, the Annelid stomodseum becomes the medullary canal, the apical 

 spot the fore-brain, and Amphioxus is a connecting link. 



Infundibular Organ of Amphioxus.t — J. Boeke calls attention to 

 the ventral group of long palisade-like ciliated cells which lies below the 

 brain in Amphioxus. They represent an infundibular organ, are homo- 

 logous with the sensory epithelium of the saccus vasulosus of fishes, 

 such as M'uraena, and they have nothing to do with the problematical 

 tuberculum posterius. 



Mites and Helminths in Relation to Tumours. J — E. Saul has 

 continued his study of the toxic and tumour-producing properties of 

 various parasites :— Bothriocephahts latus, Filaria hancrojti^ F. medin- 

 ensis, F. rhytipUuritis, Billuirzia^ Heterodera (in plants), and various 

 mites such as Fhytoptus^ Tarsonemus, Notoedres. He maintains that 

 both Helminths and Acarines must be taken into account in the setiology 

 of tumours. 



Tunicata. 



Appendicularians of the Adriatic. § — E. Uebel makes a report on 

 the Appendicularians which have been collected in the Adriatic : — 

 Kowcdevskia tenuis^ A2)pendicularia sicula, three species of Fritillaria, 

 six species of Oilwpleura, and Mef/alocerciis ahyssorum. 



* Anat. Anzeig. xliv. (1913) pp. 481-97 (10 figs.). 



t Anat. Anzeig., xliv. (1913) pp. 460-77 (12 figs.). 



X Centralbl. Bakt. Parasitenk., Ixxi. (1913) pp. 59-65 (2 pis.). 



§ SB. Akad. Wiss. Wien, cxxi. (1912) pp. 1015-38 (10 figs.). 



