5130 Fishes. 



I first obtained were straight and unbranched; afterwards I found a 

 branched condition equally common. The tubuli contained an amor- 

 phous mucilaginous fluid, with masses of globules, aggregated in very 

 unequal amount in various parts ; the larger were evidently oil spots, 

 and almost filled the diameter of the smaller tubes ; others were more 

 minute, and multitudes were so small as merely to present the ap- 

 pearance of the finest dots — these distinctly exhibited "Brown's 

 movements" — and in some instances I had fine views of the more 

 perfect circulation, termed " cyclosis." The tubuli rarely had parti- 

 tions; they ended when sterile in blunt tops, gradually tapering 

 upwards, and in oval capsules when fertile. I could trace all the 

 stages of the formation of these capsules. First the granular matter 

 developing more densely at the upper part of the tube than elsewhere, 

 so as to give it a distinct brownish colour, the top then becoming 

 dilated into an ovoid form, and the granular matter still thickening 

 and becoming separated from the ordinary contents of the tube, and 

 the septa rapidly forming by the inflexion of the utricle. Afterwards, 

 as exactly described by Unger, the fructification progressed towards 

 its development, the granular matter continuing to become more dense 

 and opaque, and in its structure numbers of comparatively clearer 

 spaces formed, which increasing, at last showed the capsule filled with 

 from twenty to fifty zoospores arranged like the meshes of a network, 

 and having still some granular matter evident at the sides of the cap- 

 sules. I then distinctly noticed a movement of the four anterior 

 zoospores* previous to their escape from the mother cell, one of them 

 applying itself to the flask-like orifice, and gradually forcing its way 

 out; evidently, as sketched, undergoing considerable pressure in the 

 process, which probably, in this instance, occupied half an hour. Its 

 escape was soon followed by that of the other zoospores, generally 

 emerging two by two, one succeeding the other with great rapidity, 

 and darting out for some distance (at least half the length of the cap- 

 sule) into the water ; they then, after a short rest, floated off right and 

 left with evident motive power, and the other cells in the capsule in 

 their turn began to exhibit independent movements and to escape ; 

 finally, the whole got out leaving the capsule empty, the process 

 taking altogether half an hour, or a little longer, for its completion. 



* This I wish to state distinctly, as I find that Alexander Braun, whose accuracy 

 of observation is so well known, states that in " Derbesia Saprolegnia and Chytridium, 

 the motion " which commonly occurs in other families, " does not become evident until 

 after the birth of the previously crowded germ-cells:" I have also been able to rerify 

 this movement more than once. 



