ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 391 



" physiological conditions existing in the bud and not in the egg 

 embryo," where the entodermic filaments are the first to be developed ; 

 this condition is evidently the need for food ; the bud embryo, unlike 

 the egg embryo, has no deutoplasm, and is therefore dependent upon 

 food brought to it from the nutritive zooids ; thus the early develop- 

 ment of the dorsal filaments which, as already stated, serve as circu- 

 latory organs ; and since the nutritive supply must evidently come 

 from below, the currents produced by the dorsal filaments work 

 upwards. 



The paper concludes with some general comparisons which are of 

 the highest interest ; it is suggested that the dorsal filaments are not 

 merely the analogues but the homologues of the alimentary canal of 

 higher animals ; if the two became fused " we should have a digestive 

 tube surrounded by closed cavities, in the walls of which are developed 

 the muscles." This fusion does actually take place temporarily during 

 digestion, and in Alcyonium the filaments appear sometimes to fuse 

 permanently. In this case the " radial chambers of an Anthozoan 

 correspond to the mesodermic diverticula of Enterocoela," a view which 

 has already been set forth by several morphologists. With the 

 exception of the Haimeida, all Alcyonaria show a marked bilateral 

 symmetry, and the radial chambers may be considered as the unpaired 

 diverticula and a series of lateral paired diverticula ; the latter may 

 perhaps be compared to the somites of segmented animals. It is well 

 known that a ciliated groove exists on the ventral side of the CBSophagus, 

 and if this portion were to become separated off from the rest of the 

 oesophagus and the mesenterial filaments fused, the result would be an 

 "animal with a stomodsBum and proctodeum, a closed mesenteron, 

 and paired mesoblastic somites." 



Anatomy of Peachia hastata.* — M. Faurot recommends that this 

 Anthozoon be first rendered insensible by water charged with carbonic 

 acid. He finds twelve mesenterial folds, perforated at the level of the 

 oesophagus ; two neighbouring folds, instead of floating freely in the 

 general cavity, unite to form a grooved organ, which has externally 

 the appearance of a papilliform lip, and ends in the general cavity a 

 short distance from the inferior orifice, which Peachia, like CeriantJius, 

 possesses. Eight muscular bands project on the internal wall ; these 

 are arranged by pairs, so that four only of the twelve chambers are 

 provided with them. These four chambers are placed asymmetrically, 

 two of them being situated on either side of the grooved organ, and 

 the other two being set opposite, on an axis perpendicular to that 

 which passes through the papilliform lip and the inferior orifice. 



Ephyrae of Cotylorhiza and Rhizo stoma.! — C. Claus has been 

 able to study a swarm of Cotylorhiza in all stages of the Ephyra phase ; 

 the youngest were from 1^ to 2 mm. in diameter, with eight long 

 slender lobes, the cleft pieces of which were rounded rather than 

 pointed. They are to be distinguished from the ephyrte of Aurelia 

 or Chrysaora by the yellow algal cells, which, when accumulated in 



* Comptes Kendus, xcviii (1884) pp. 756-7. 

 t Arbeit. Zool. Inst. Wien, v. (1884) pp. 175-83. 



