May 1, 1865.J 



S.OIENCE-GOSSIP. 



101 



even with his greatest care and contrivances he could 

 seldom obtain them, without the mere pressure or 

 friction in drawing tliem up through the water 

 causing the pseudopodia to collapse and shrink, a 

 change to take place in the oil-globules, as he calls 

 them, of the sarcode, when death speedily ensued. 

 He found, however, that in the globe, or bell-shaped 

 species, such as the Eucyrtidiums, the sarcode sub- 

 stance was divided iuto four lobes or flaps {lappeii) ; 

 and Dr. Carpenter follows this idea in the very short 

 notice he takes of Polycystiua as a sub-order of 

 Ehizopods. MiiUer says, in the inside of the shell 

 the animal-substance consists of four folds arranged 

 round a central axis, which reaches more or less 

 deeply within the bell. The innermost part of these 

 lobes contains one or more oil-like balls ; and in the 

 under-part, nearest to the open side of the shell, are 

 some brown-yellow cells, and with them are also 

 other cells or transparent spaces, or vacuoles, Avhich 

 have been conjectured to shadow forth the first 

 incipient symptoms of circulation. 



Kg. 65. 



■Ehopalocanium or.vatum. 



It would be too long to name all the various 

 external shapes of the shells; bat among the most 

 striking differences of form may be mentioned that 



some are like numerous httle globes growing out of 

 each other, beginning with a small one at the apex, 

 and each increasing in size as they descend, some- 

 times so gradually as to look like storied beehives 

 piled up one on the other. In others, the globes or 

 bells dilate greatly and rapidly towards the base, 

 till the lowermost exceed in width the most out- 

 rageous crinoline! Then there are single round 

 balls pierced through and through with spikes 

 sticking out in all directions, but ever pointing from 

 the centre. Again, to compare small things with 

 great, there are shapes of the Egyptian pyramids, 

 and others stretched out and narrowed into obelisks. 



Different from all these, are very numerous flat- 

 tened disks, which appear to grow m concentric 

 circles, some becoming bordered, others spiked round 

 the edges, and many having very extraordinary 

 radiating arms in endless variety. 



A very remarkable feature in the Polycystins is 

 their exuberant out-grov)ths. Sometimes there are 

 merely spines projecting in a tolerably regular, and 

 always radiating manner; but sometimes these 

 spines or projections branch out and subdivide in 

 the most whimsical arborescent forms, so as to 

 assume the shapes of stags' antlers, or even the 

 more complicated deHcate branchings of the once 

 famed bedeguar of the rose (which we used to seek 

 out in childhood's days, and call Robin-redbreast's 

 pillow). Apparently these spines of the Polycystms, 

 whether simple or compound, always are to a certain 

 extent hollow, so as to have been permeated by the 

 sarcode substance during their growth ; sometimes 

 instead of becoming finely attenuated, they become 

 bulbous at their points ; and these bulbils swell, 

 become cellular or foraminated, and assume very 

 much the appearance as if they were gemmse from 

 the parent, and mtended to break forth and com- 

 mence life as fresh individuals. Very remarkable 

 instances of this simulation of " continued gemma- 

 tion," as described by Dr. Carpenter as an attribute 

 of the newly-discovered Hozoon of the Canadian 

 rocks, occur in the Polycystinic forms called by 

 Professor Ehrenberg Astrommas and Siepluniastrums: 

 in these a central spheroid body is enveloped by a 

 sort of fine siliceous web or sponge, which gradually 

 breaks away as the centre sends forth stalks (three 

 to six, but normally four), celled and chambered as 

 complicately as any foraminifer ; and pushing their 

 way through the sponge-like envelope and beyond it, 

 their ends become club-shaped, often strongly spiked 

 at the extremity, but the swollen part containing 

 what looks like a redupKcation of the central parent- 

 form ; and these seem as if they might possibly 

 break away, and become in their turn centres of 

 growth. 



If comparatively but few of these organisms have 

 been systematically examined in a living state, count- 

 less multitudes of their skeletons have, been re- 



