290 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



luca) he found that this matter was secreted by glands, pos- 

 sibly special for this purpose, but more probably the phos- 

 phorescence is a secondary property. Further, the secretion 

 contains epithelial cells in a state of fatty degeneration, and 

 it is these fatty cells, and the fat which they give rise to, 

 which are phosphorescent. Hence the phosphorescence of 

 marine animals is brought under the same category as the 

 phosphorescence of decaying fish and bones, being due to the 

 formation, in decomposition, of a phosphoric hydrocarbon, or 

 phosphureted hydrogen itself. In Pennatula Professor Pan- 

 ceri has made phosphorescence the means of studying a more 

 important physiological question, namely, the rate of trans- 

 mission of an irritation ; for when one extremity of a Pen- 

 natula is irritated, a stream of phosphorescent light runs along 

 the whole length of the polyp colony, indicating thus, by its 

 passage, the rate of the transmission of the irritation. A 

 careful study was also made by Professor Panceri, by means 

 of the spectroscope, of the light of phosphorescence. 12^4, 

 December 14, 1871, 132. 



PHOSPHORESCENCE OF PYKOSOMA. 



Professor Panceri, of Naples, to whose experiments upon 

 marine animals we have had frequent occasion to refer, has 

 lately published an account of certain observations upon 

 Pyrosoma, a transparent compound ascidian found floating 

 in shoals both in the Atlantic and Pacific Oceans. This is 

 among the most luminous of marine invertebrates, and Pro- 

 fessor Panceri has ascertained that the light-emitting organs 

 are two large granular patches, placed on either side, near 

 the mouth of each of the tunicate constituents of the com- 

 pound mass. He also ascertained that from a single egg 

 four embryos are developed, while the " cap" to which they 

 are attached represents a fifth embryo, which attains its de- 

 velopment first, has a mouth, nervous* system, and a heart 

 that pumps blood into the chain of four embryos encircling * 

 it. 1 5 A, April 1 3, 1872, 466. 



PRESERVATION OF JELLY-FISH. 



All marine zoologists are aware of the difficulty experi- 

 enced in preserving certain forms of marine animals, the jelly- 

 fishes especially, so as to exhibit them in their natural shapes 



