68 W. ARCHER. 



23, n), whose length approaches one third to one fourth the 

 diameter of the body ; towards the margin of the latter occur 

 one or several vigorously pulsating contractile vacuoles (figs. 

 21 and 22, c c). The pseudopodia do not subdivide ; they 

 show a distinct granular current ; sometimes even minute 

 vacuoles could be seen passing up and down them. 



As regards reproduction, the authors record simple fission 

 as readily to be observed. They frequently saw two bodies 

 of about equal size within one and the same shell, each pro- 

 vided with its nucleus, and possessing its contractile vacuoles. 

 Once they saw a small individual, which, no doubt, pro- 

 ceeded from self-division, furnished with a minute stipes, but 

 still without a shell (fig. 22). The plane of division stood 

 vertical to the direction of the stipes. Besides subdivision, 

 encysting occurs, but the authors were unable to follow out 

 any further development. 



Clathrulina elegans, Cienk.^ (vol. xvi (1876), PI. XXII, 

 figs. 23—25). 



Cienkowski was disposed to regard the perforate hollow- 

 globular skeleton of this now pretty-well known form as 

 composed of numerous polygonal plates. This view Hertwig 

 and Lesser seem rightly to contradict ; it certainly seems to 

 be but a single connected structure throughout; the openings 

 are roundish-polygonal, and their margins surrounded by a 

 more or less elevated rim, which in fully-grown examples 

 can be seen at the equatorial periphery of the sphere stand- 

 ing off like papillae or very short blunt spines. The stipes 

 is regarded by Hertwig and Lesser as tubular ; so it cer- 

 tainly appears to be, its base can be often seen to terminate 

 in a number of rootlike processes by which it retains a hold 

 on foreign supports, or indeed often on the shells of other 

 individuals of its own species. As to the sarcode body as is 

 known, it is comparable to Actinophrys, but as the original 

 discoverer, Cienkowski (I believe I myself found it, however, 

 considerably prior to him, and showed it at a meeting of the 

 Dublin Microscopical Club and this considerably in advance 

 of the date of my own paper, preceded by Cienkowski's only 

 by a very short interval) observes, unlike that of that form, 

 that here the peripheral contour passes into a number of 

 short lobelike projections terminating in the pseudopodia. 



Hertwig and Lesser distinguish between two kinds of 

 vacuoles — one enclosing food- particles, the other simple fluid- 

 cavities ; the latter mostly projecting at the periphery in a 

 somewhat hemispherical manner and are partly contractile. 

 • Cieukowski : ' Archiv f. Mikrosk. Anat.' Bd. Ill, p. 311, t. xviii. 



