612 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
grannies, which are hidden in the dark larvae, are seen to be abundant 
and much ramified, and apparently unaffected by the warmth. 
Fischel’s account of the development of the pigment is briefly as 
follows. Within the cells which become chromatophores abundant 
granules are formed. These granules are at first light, and may be 
called “ Pigment-bildner,” for they assume a dark colour as the cells 
become larger and more branched. The characteristic dark granules 
arise either by a specific change in their predecessors or by the pene- 
tration of these by a new pigment. The varieties observed seem to 
show that the chromatophores can change their content of pigment, in 
short, that the pigmentation is involved in the metabolic changes. 
At the end of the paper there is a useful bibliography. 
Distribution of Pelagic Animals.* — Prof. Fr. Dahl devoted 2-4 hours 
a day, on his voyage to the Bismarck Archipelago, to counting the animals 
visible from aboard ship. He gives tabular summaries of his observa- 
tions, which related to dolphins, birds, sea-snakes, flying-fish, Janthina, 
Pelagia , and Porpita, and suggests that much useful information would be 
gained if the method were carefully and systematically pursued. Thus 
more might be readily discovered in regard to the occurrence of animals 
in swarms. From Dahl’s notes we select the following : — During seven 
days on the Mediterranean (in March) no animals were seen except 
Delphinidie and birds. During the whole voyage there was no observa- 
tion of Physalia or Velella. One day flying-fish were seen at the rate of 
sixty per minute ; the vibration of their fins only occurs when the tail 
strikes the water. 
Tunicata. 
Budding in Compound Ascidians.j — Mr. W. E. Bitter commences 
with the account of a new species which he calls Goodsiria dura, found 
by him at Santa Barbara, California, where specimens were obtained in 
abundance, and in a perfectly free condition. He finds that in this 
form the budding is pallial, and that the buds arise far forward on the 
parent zooid. In no case was more than one bud found on the same 
parent. These buds became wholly separated from their parent at a 
very early stage, that is to say, before any differentiation of the organs 
begins ; at a considerably later time they become secondarily connected 
with the vessels of their parent. The formation of the branchial and 
peribranchial sacs and of the digestive tract does not differ in any 
essential particular from that of all other Compound Ascidians. The 
common rudiment of the pericardium and heart is derived from the wall of 
the endodermic vesicle by an imperfect evagination that does not become 
fully separated until the ventral folds which separate the peribranchial 
sacs from the branchial sac have reached back to the region where the 
heart is forming. The ganglion in this species, as in Botryllus , lies 
ventrally to the hypophysial duct. The youngest sexual cells observed 
were found free in the body-space of the buds, so that in all probability 
they pass from parent to bud, as is the case in Botryllus. 
Mr. Ritter has also made a study of the budding in Peropliora 
annedens. The general conclusions to which he is led by his observa- 
* SB. K. Pieuss. Akad., 189G, pp. 705-14. 
t Journ. Morphol., xii. (189G) pp. 149-238 (6 pis.). 
