34 Mr. H. J. Carter on 



ing its presence tlian iias heretofore been employed becoming 

 obvious when, as shown by me in the case of Oromia (and as I 

 believe will be found to be the case in every one of the naked 

 Rhizopods which have hitherto been relegated to the lowest 

 order of that group of organisms chiefly on account of being 

 supposed to be deficient in this organ) , it is almost certain that 

 the error has arisen from the extreme difficulty, often encoun- 

 tered, of rendering the nucleus visible. The superiority of the 

 method I am about to describe consists in its being simple, 

 easy of application, and sure. 



During some experimental trials I was making on the effect 

 of a galvanic current passed through the water on slides con- 

 taining living Amoehce and other organisms, which generally 

 resulted in their being instantaneously killed without render- 

 ing their internal organization more distinct than it was before, 

 it occurred to one of my sons to try the effect of ordinary 

 frictional electricity. The result proved most gratifying ; for 

 although, as in previous cases, the Amcebce were instantly 

 killed, their entire bodies were at the same time burst up, so 

 to speak, into a homogeneous-looking mass of granular parti- 

 cles, the nucleus, however, in every instance forming a con- 

 spicuous object in the midst of these. So marked was this 

 result that in some perfectly clean gatherings of RapMdio- 

 phrys elegans, so numerous that each field of the microscope 

 was simply crowded with them, but in none of which a nucleus 

 could be previously discerned, the instant the discharging 

 knobs communicating with a single small Leyden jar were 

 applied on opposite sides of the glass cover, and of course in 

 contact with the water between the cover and slide, the effect I 

 have described was produced in every one of them. The only 

 precaution that has to be attended to is not to employ too 

 powerful a discharge. 



VI. — Descriptions of Sponges from the Neighhourhood of Port 

 Phillip Ileadsy Sojifh Ai(straUa^ continued. By H. J. 

 Carter, F.R.S. &c. 



[Continued fi-om vol. xvii. p. 516.] 



Order VIII. CALCAREA {continued). 



Observation. 



Following Pol^jaeff's arrangement the Sy cones will be 

 inserted here, that is before the Leucones, as the radial cham- 

 bers in the simplest and most typical forms, ex. gr. Grantia 

 ciliata^ Bk. [Sycandra ciliata, H.), appear to be closely allied 



