666 SUMMARY OF CURRENT RESEARCHES RELATING TO 



differ en tiated stage, we cannot regard the gonopliore or the medusa 

 as a sexual form or as representing the sexual generation. The 

 author further insists on the view that a s]>orosac and a medusa are 

 morphologically identical. 



In answer to the question — If the products arise in the polyp itself 

 and not in the so-called sexual buds, what are the sporosacs or 

 medusae? the author answers that they are individuals specially 

 adapted for reproduction, which receive their sexual elements and 

 insure their safe development; but they do not give rise to them. 

 These elements arise in the colony itself and it is, therefore, im- 

 possible to regard the gonoiDhores and meduste as individuals which 

 alone are sexual, in opposition to the polyp, which is generally 

 regarded as the asexual individual. In other words, alternation of 

 generation does not really obtain in the species examined by M. de 

 Varenne. 



The author finds that the mother-cells of the spermatozoa are 

 endodermic in origin, and that there is no exception to this rule. 



The history of Podocoryne carnea is followed out in detail, and 

 the conclusion arrived at that, in species with free-swimming medusas, 

 the develo]3ment of the ovum is exactly similar to that which obtains 

 when the gonophores remain fixed to the colony. 



New Hydroid Polyp.* — Prof. E. D. Cope describes an interesting 

 form of hydroid polyp found in large numbers on the bark of sub- 

 merged trees in Upper Klamath Lake, Oregon. Its coenoecium is 

 a mass of creeping yellowish stems imbedded in sarcode. Each zooid 

 is of an elongate oval form, sessile, and with six rays of equal size, 

 each oue-ha]f as long as the body. The zooids are translucent, but 

 with two oval bodies in the lower half of the body-cavity of a yellow 

 colour. These are collected in masses as large as the fist. The 

 length of eacli zooid is 1 mm. They did not extend themselves 

 beyond this length, neither did the rays elongate to beyond half the 

 same during the time they were observed. They retracted themselves 

 on being irritated. They do not possess any fringes like the arms 

 of the Polyzoa. As the possession of a coenoecium distinguishes this 

 genus from all the fresh-water hydroids, it was proj)osed to dis- 

 tinguish it as the type of a new genus with the name Bhizohydra, 

 the species being nmaed. Jlavitincta. An attempt to preserve some of 

 the masses of zooids in alcohol was not successful. 



Hard Structures of the Fungiidae.t— Pi'of. P. M. Duncan has 

 followed up his recent study of the corallum of the sub-family 

 LophoserincB by that of the twin sub-fiimily of the Fungiidce, viz. the 

 Fungiince. As in the former case, the synapticula have received most 

 attention, and the general res^ult of the investigation is to confirm and 

 enforce the great morphological importance originally attributed to 

 these structures by Milne-Edwards and Haime. In Fungia scutaria 

 var., this is shown by several circumstances: (1) the co-existence 

 with synapticula of the usual granules of the surface of the septa, 



* AcaJ. Nat. Sci. Philad., 1883. 



t Journ. Linn. Soc. (Zool.), xvii. (1883) pp. 137-62 (2 pis.). 



