1880. | Development of Amphioxus Lanceolatus. 7 
All of the above-mentioned specimens which came into my 
possession, were gathered together during the period from the 
oth of July, when the first specimen, an adult, was obtained, to 
the 2d or 3d of August, after which date no more could be found. 
The young were taken mostly at night, one or more at a time, 
when the water was comparatively quiet, but the greatest number 
captured on any one occasion was at noon of a very hot day, 
when there was scarcely a breath of wind, and the surface of the 
bay was almost as smooth as the proverbial “ sheet of glass ;” 
these small inhabitants thus seeming to be affected by heat, and 
especially by a quiet condition of the water, in very much such 
a manner as are the myriads of other young animals which are 
floated hither and thither by the currents of the sea at this sea- 
son of the year. As soon as taken they were transferred to 
tumblers which had been previously filled with fresh sea-water, 
and each tumbler was generally occupied by four or five speci- 
mens. The water was changed daily in all the vessels. When 
first placed in these receptacles they darted about with a quick 
“ wiggling ” motion which resembled somewhat the movement 
of a tadpole, but different in that the head, or anterior part of the 
body, moved from side to side as far and as vigorously as the 
tail portion. This peculiar undulation was generally kept up for 
some little time at or near the surface, when suddenly they would 
cease all motion and allow themselves to sink slowly to the bot-. 
tom, where they would remain flat upon their sides until again’ 
impelled to action. When this impulse came, from whatever- 
cause, and they were once started from their resting place at the 
bottom, they generally swam directly upward.to the surface, moved) — 
about here for a short time, and then, as before, suddenly stopped 
and allowed themselves to sink again to the bottom. But some- 
times one of the inhabitants of a dish would start up, seemingly 
impelled by some willful freak, dash about close over the bottom. _ 
and stir up all the others in the vessel, when there would be, for a; 
moment or so, quite a brilliant display of undulating, flashing 
forms. ao 
The largest of these young specimens was pretty well adoi 
in development, and was placed in a separate dish which had a 
layer of sand upon the bottom. It- was thus isolated for the pur. 
pose of ascertaining if it would make use of the sand as a place: _ 
of refuge, but only on one or two occasions, and then for, ma 
