cliv GENERAL SUMMARY OF SCIENTIFIC AND 



lades those hypothetical mesozoa which are formed from a many- 

 celled sphere, constituted like a Magosphmra (Haeckel), and in which 

 the two cellular layers are developed by delamination. He there- 

 fore divides the animal kingdom into three primary groups i.e.^ 

 the Protozoa^ the Mesozoa^ and the Metazoa. 



It appears that a species of Cainpamdaria, a hydroid medusa, has 

 been found in Greenland by the Valorous on its return from Disco, 

 which is said to be identical with one found by Mr. Eaton, of the 

 British Transit of Venus Expedition, at Kerguelen Island ; while 

 the deep waters of Davis Strait afford a shell which was long since 

 found fossil in the newer tertiary beds of Sicily, and was supposed 

 to be extinct. 



The animal of the coral, Millepora, was by the late Professor Agas- 

 siz regarded as a hydroid polyp, or je'lly-fish, rather than a true coral 

 polyp. Now, however, it has been shown by Mr. Moseley, of the 

 Challenge?' expedition, who studied the Millepora at Bermuda, that 

 the animal is probably a true polyp. He says that the examina- 

 tion of the Millepora is beset with serious difficulties ; but he ob- 

 served that there are large and small polyps, that both kinds have 

 tentacles, and appear to be four in number and to be compound. 

 Before this, however. General Nelson, of Bermuda, had made draw- 

 ings of the animal of Millepora, upon which the following comments 

 have been made by Professor Duncan, of London, in Nature : " It is 

 a satisfaction for me to be able to state that General Nelson's draw- 

 ings prove that Agassiz saw a part of the polyp, and that Mr. Mose- 

 ley's beautiful delineations, far in advance of all, testify to the cor- 

 rectness of my fellow-worker. I do not credit the hydroid nature 

 of the polyp now, any more than I did when writing the reports on 

 the British fossil corals, and I believe Millepora to be an Actinozoan." 



The effect of certain poisons on Mednsm is described by Mr. G, J. 

 Romanes in the Proceedings of the Roval Societv. He states that 

 strychnia exerts a very marked influence upon them. " Of the spe- 

 cies I have met with, Cyanea cainllata is the most suitable for show- 

 ing the effects of this poison, from the fact that in water kept at a 

 constant temperature the normal pulsations of this animal are as reg- 

 ular as those of a heart. Shortly after a solution of strychnia has 

 been added to the water in which a specimen of C. capillata is con- 

 tained, unmistakable signs of irregularity in the pulsations of the 

 animal supervene. This irregularity then increases more and more, 

 until at last it grows into well-marked convulsions. The convul- 

 sions manifest themselves in the form of extreme deviations from the 

 rhythmical character of the normal contractions, amounting, in fact, 

 to nothing less than tonic spasms. It is further of importance to re- 

 mark that the convulsions are very plainly of a paroxysmal nature, 

 prolonged periods of uninterrupted convulsions being every now 

 and then relieved by shorter periods of repose, during which the 



