580 DR. J. B. HICKS ON THE GONIDIA AND 



possibility of their segmenting. It is lioped that the following observations may tend to 

 throw some light upon the question, and to reconcile the conflicting evidence of these 

 great observers, upon which I shall more particularly dwell in reviewing the points of 

 interest in this paper. 



During the years 1859-60 I grew Moss under glass. The various branches threw out 

 numberless confervoid filaments, some of which approached the radicular rather than 

 the confervoid type. However, it was in both that I observed that each of the bodies 

 which corresponded to the " chlorophyll-utricles " of other parts possessed the power of 

 enlarging. This is drawn in PL LVIII. fig. 23 a. In PI. LVIII. fig. 23 h are shown 

 two portions of filaments, with the chlorophyll-granules just beginning to show con- 

 sistence on their exterior. This was best noticed in those which were escaping from a 

 broken cell. At c is shown a number of these cells in various degrees of growth ; and it 

 was easy, by comparing the contents of the various cells, to see that the smaller possessed 

 the same origin as the larger. 



As they increased, they showed a more distinct outline ; and it was clear that, whatever 

 doubts might attach itself to the existence of a membrane on the exterior of the chlo- 

 rophyll-utricles of the leaves and ordinary confervoid filaments, these contents were 

 enclosed by a delicate envelope : and as they further enlarged, a nucleus appeared in the 

 centre. After a time, the parent cell broke up, and these once chlorophyll-utricles, but 

 now distinct cells, became free. 



In the undisturbed condition in which they existed, and being held together by the 

 gum-like character of the residue of the parent-cell wall, they of course did not spread 

 far ; and as the filaments had attached themselves to the sides of the glass, I had an 

 excellent opportunity of watching their subsequent progress. 



After increasing gradually in an oval form, they arrived to about the ttVo i^^ch in 

 size, when they began to segment into two, or three, or four divisions, or even into more 

 (PI. LVIII. fig. 22 cZ), a nucleus appearing in each division. 



When the resulting cells were two or three, they were almost always oval, the Hne of 

 separation taking place obliquely in the oval parent cell (PI. LVIII. fig. 23 c?). When, 

 however, the secondary cells were more than that, then they formed around a common 

 axis. At this period the cell-wall of the parent cell (once chlorophyll-utricle) was very 

 marked. 



After they had remained some months in a state of nearly complete quiescence, I placed 

 some of these segmenting cells into water on a slide, and, covering them with ordinary 

 thin glass, I put them in the sun for about an hour. To my great surprise, I found the 

 tohole water alive with zoospores. There were thousands in the square inch, in a most 

 active state. Purther examination showed that the segments had been released by the 

 bursting of the parent-cell waU, and had now become these zoospores. After a time they 

 came to rest, and altogether lost their activity. I preserved the slide for some time, but 

 J could not determine anything very definite as to their after-life, beyond that they came 

 to rest, lost their cilia, and again subdivided. 



These zoospores were of light-green colour; they differed slightly in size, and were 

 principally oval ; some, however (and these were the larger), were round. They possessed 



