878 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the latter ; the inner surface is not seen to be ciliated until after the 

 fixation of the larva. The enteric tract undergoes a number of con- 

 siderable changes before it attains its definite form. At the hinder 

 end there appears a new organ — the gland which surrounds the 

 enteron; it is formed as a diverticulum of the mid-gut, and it is 

 possible that it has the functions of some kind of " liver." The later 

 stages of development are, as may bo supposed, those in which the 

 gill-clefts are to be seen increasing in number. 



Tunicata of the 'Triton.'* — The most interesting point in Prof. 

 W. A. Herdman's report on the Tunicata of the Faeroe Channel is 

 that which deals with Doliolum denticulafum, of which between five 

 and six thousand specimens were collected ; they all belonged to the 

 sexual generation. The best specimens for histological study were 

 those which had been preserved in chromic acid, and which were 

 thoroughly washed in alcohol, stained in picrocarmine, and mounted 

 in Farrant's solution. The test is almost absent ; the first and last 

 of the eight muscular bands form sphincters for the apertures of the 

 body. The nerve-ganglion, which is small, gives off four large nerve- 

 trunks, and smaller nerves between them. As in all other Tunicata, 

 where the matter has been investigated, the nerve-cells are all in the 

 outer layer of the ganglion, and the centre is formed of a mass of 

 delicate interlacing fibres and granular matter. The transverse 

 muscle-bands of the heart appeared to be composed of a large number 

 of very fine fibres, and not of one only, as supposed by Keferstein 

 and Ehlers. 



Two glandular systems, which appeared to be quite distinct, were 

 found connected with the alimentary canal ; the first, which does not 

 seem to have been hitherto noted, lay along the ventral surface of the 

 stomach and first part of the intestine ; it consists of caeca, which 

 branch and occasionally anastomose; no duct or opening into the 

 alimentary canal was detected. 



Prof. Herdman asks whence all the Doliola have come, and where 

 are the asexual forms from which they have been produced; the 

 nature of the area — whether warm or cold — has apparently no in- 

 fluence on them, but the questions put cannot yet be answered. Mr. 

 Missing noted that on August 5, 1882, Doliola were abundant, and 

 AcantJiometrce, which in 1881 had been present in enormous multi- 

 tudes, were absent from the surface gatherings. On August 7 the 

 conditions were reversed. The Doliolce were most abundant at 5 or 

 6 fathoms beneath the surface ; at times they appeared in vast banks, 

 between which there were always a few stragglers ; the animals were 

 observed to be phosphorescent, and the discharges appeared to follow 

 the direction of the nerve-cords or filaments. 



Organization of Anchinia.f — N. Wagner describes a phase of the 

 development of Anchinia rubra characterized by a regularly globular 

 form of body; moreover, the long caudal appendage of the form 

 hitherto known is wanting. This phase is agamous. Individuals 



* Trans. Eoy. Soc. Edin., xxxii. (for 1882-3) pp. 93-117 (5 pis.), 

 t Comptes Eeudus, xcix. (1884) pp. (J15-6. 



