278 T. C. WHITE Off THE LIFE-HISTORY OF BOTRYLLOIDES. 



or patch was of irregular shape, about the dimensions of a florin 

 (Fig. 1), having its borders marked by numerous capes, headlands, 

 and bays, while scattered throughout its substance were freely dis- 

 tributed a great number of granular bodies, that under the low 

 magnifying power of a pocket lens, appeared like calcareous spicula, 

 aggregated into little groups. The Tunicata were disposed irregu- 

 larly throughout the coasts of this patch, and not in accordance with 

 the stellar arrangement generally figured in Botryllus, but in small 

 knots of from four to six zooids, sometimes a zooid would occur 

 singly ; from the numerous headlands springing from the borders of 

 this patch, pseudopodic processes could be observed stretching out 

 like the tent ropes of a marquee, but these were not fixed perma- 

 nently, but would be found altered from hour to hour, and from day 

 to day. 



Long and patiently I looked at my specimen, trying by every con- 

 trivance suggested to my mind, to bring my microscope to bear on 

 my colony, that I might learn more of its internal economy, and 

 that I might study some of the secrets of its reproduction and de- 

 velopment, but without avail. The most I could see was the con- 

 traction ever and anon of the branchial sacs of the enclosed Tuni- 

 cata. Meanwhile my patch, without increasing in size, was slowly 

 moving up the front of the aquarium, whether by means of its 

 amseboid pseudopodia, or by any other means, I could not discover, 

 but it nevertheless had moved a distance of nine inches. It had now 

 been about four months performing this journey, when a thinning 

 took place in the centre of the patch, which thinning increased daily 

 till the patch became an open ring, and this ring then became 

 narrower, at the same time that it extended itself to about three 

 inches in diameter, the tent ropes still forming a marked feature both 

 within and without the ring. Now sometimes a single Tunicata 

 would be seen at the end of one of these pseudopodic processes, and 

 I would look forward to an approaching opportunity of isolating it 

 for microscopical examination, but only to find that after a few hours 

 it would be drawn back again into the general mass. At length the 

 ring began to break up into detached portions (Fig. 2), and I was 

 then enabled to take one of these islands (Fig. 3 J, and make a care- 

 ful microscopical investigation into what I had patiently waited for 

 months to ascertain — viz., by what method of locomotion this mass 

 was able to transport itself from the bottom of my tank to the top. 

 The first observations I was fortunate enough to make, related to 



