Scientific Intelligence. Zoology. 395 



circle, heat and feeling of uneasiness came on, and I found 

 it necessary to spring out of my bed. As soon as a light was 

 brought every thing became again stationary, and the disagree- 

 able sensations vanished. During the whole day, while under 

 the influence of light, I had been able to follow my usual avoca- 

 tions, without perceiving the slightest symptoms of an unhealthy 

 over-excitement. 



13. Ehrenberg on Masses of Polyparia without Animals. 

 " The sponges and alcyons," he remarks, " are not polypiferous 

 masses deprived of their polypi, because, at no epoch of their 

 growth do they shew a structure which indicates the presence 

 of animal bodies ; and, besides, the marine sponges have repro- 

 ductive granules, and consequently are true plants. When 

 studying, eight months ago, at Berlin, the Sertularia dichotoma 

 of the Northern Ocean (a polypiferous mass which M. Cavolini 

 had never succeeded in preserving alive in vessels filled with 

 sea-water), he distinctly observed the death or periodical decay 

 of all the animal corals (corolles), and also the formation of new 

 buds after a certain time. The branchy twig was thus then, 

 during a certain time (fourteen days to a month), entirely de- 

 prived of living animals, although it was itself alive. This phe- 

 nomenon, however, did not exhibit itself except in those twigs 

 in which a part of the animals now dead had previously retired 

 into the central and hollow part of the stalk. The minute exami- 

 nation of this internal part demonstrated to me, that it contained 

 many systems of animal bodies, of intestinal canals, also granular 

 masses (were they the male seminal glands ?), and longitudinal 

 and transversal muscular threads, endowed with contractility." 

 He presumed that the other organs of the bodies of the polypi 

 also existed in the mass, though the great difficulty of the exa- 

 mination prevented him from making the direct discovery. The 

 polypiferous masses, thus deprived of their living inhabitants, 

 who, so to speak, according to Cavolini, hybernate, though they 

 still periodically produce polypi, are not simple animal substances 

 individually developing themselves, but animated masses which 

 possess as a whole, and, in their integrity, the sum of the animal 

 organs of a complete system, and which completely perish when 

 these come to be altered. It is the same method of reproduc- 

 tion, though differing in some slight particulars, as takes place 



