892 RECORD OF CURRENT RESEARCHES RELATING TO 



of the latter group ; as to the former point it is to be observed that 

 conogenetic arrangements obtain very largely ; the history of the 

 germ is compressed and simplified, owing, doubtless, in large measure 

 to the great development of the food-yolk. The results, however, of 

 the elaborate comparison which has been instituted between the 

 organs of the Ctenophora and of the Authomeduspe seem to make it 

 highly probable that the Ctenoj^hora took their origin in the Cla- 

 donemidae, and had for their ancestors Hydroid polyps of the Tubularian 

 group. 



The author finally remarks that the most important ontogenetic 

 character in the Ctenophora is that the funnel is the first organ to 

 aj^pear, and that from this there are given ofl:" four peri-radial canals, 

 which, by bifurcation, give rise to eight adradial ones. It is only 

 after this that the so-called stomach, which is invested by ectoderm, 

 apjiears. 



Zoantharia malacodermata of the Coasts of Marseilles.* — M. 

 Jourdan gives a short account of his investigations into the structure 

 of these animals, in which he points out that the walls of their body 

 consist of three layers, (1) an external cellular layer or ectodermic ; 

 (2) a fibrous and mesodermic ; and (3) cellular and eudodermic. 



In the ectoderm there are to be found among other structures 

 epithelial elements which are probably sensitive and are apparently 

 " analogous " to the chromatophore-pouches found in Actinia equina ; 

 the presence of neuro-muscular cells is, it may be noted, distinctly 

 reported. The structure of the mesodermal layer of Ceriantkus was 

 found to be different to that of the other zoanth malacodermata ; it is 

 stated to be composed of a thick muscular layer covered in by two 

 planes of connective tissue ; there are in it smooth muscular fibres 

 which are longitudinal in direction and are arranged in radiating 

 laminae ; below the internal fibrous layer there is a layer of circular 

 muscular fibres. The fibrous layer of Calliactis is stated to be ex- 

 ceptionally thick and to be traversed by permanent pores in addition 

 to being provided with a number of spots of circular muscular fibres 

 which seem assuredly to act after the manner of a sphincter. 



The tentacles, which have the same structure as the walls of the 

 body, are characterized by the presence of a layer of longitudinal 

 muscles subjacent to the ectoderm ; the oesophageal walls have like- 

 wise the same structure as the body-walls, but their external cellular 

 layer is remarkable for the presence of special glandular elements. 



M. Jourdan promises more detailed observations. 



Blastology of the Corals.f — Dr. W. Haacke, of Jena, deals with 

 this subject in a paper which is couched in the language of Haeckelian 

 morphology. After pointing out the absence of any good evidence as 

 to the metameric characters of the corals, the author states that ho 

 regards the typical form as being a simple pyramid, the base of which 

 corresponds to the oral and the apex to the aboral end of the body of 

 the coral " jj^^^son." 



* ' Coinptus Eendus,' Ixxxix. (1879) p. 452. 

 t ' Jeuais. Zeitschr.,' xiii. (1S79) p. 2(39. 



