50 



ooecia, is John EUisS who in his well-known work on the Corallines not only 

 treats of the hydroid polyps, coral algae, various Octadiniae, sponges etc., but also 

 of a number of Brgozoa. In a number of species of the genera Bugula, Bicellaria 

 and Scmpocellaria he has noticed and figured the ocecia, which he terms »Balls, 

 testaceous Spherules*, or ^testaceous Figures^ '; but while he recognised, although 

 in an imperfect way, the importance of the gonothecae for the reproduction of 

 the hydroids polyps^ (»I discovered that they were Matrices or Habitations of 

 young Polypes, which are produced here and there, on the Sides of the Parent, 

 as in the Freshwater Polype*), he does not seem to have reached to a similar 

 comprehension of the ocecia. He only speaks in detail about the ooecia of a tropi- 

 cal Bugula species, B. neritina^ and expresses here the very remarkable view 

 that they are a sort of small snails, from the eggs of which the colony originates : 

 »I plainly discovered it to be the connected Niduses or Matrices of certain testa- 

 ceous Animals, like small snails or Neritse* ... »0r let us suppose, that the 

 testaceous Animal . . . lays its eggs; these turn into vermicular-shaped Polypes, 

 which, after they have fixed themselves to some marine Substance, rise up, and 

 push forth into branches of small Polypes in their Cells*. The ooecia are thus 

 figured on the accompanying drawings as small Spirorbis or Planorbis, and from 

 this description Linne gave to this species the name y>nentina<. Ellis expresses 

 elsewhere a supposition that a similar relation obtains between certain Brgozoa 

 and Bivalves: »The next class, which is the Eschara deserves our notice« . . . 

 »There appears a great probability of some of these being the Matrices or ovaries 

 of certain Species of Shellfish, perhaps of the Bivalve Kind*- On Flustra (Eschara) 

 foliacea he further writes^: »Upon examining some specimens lately, I discovered 

 at the Entrance of many of the Cells a small testaceous Body, like a bivalve 

 Shell*. As appears from the figure to which the writer refers, there is no ooecium 

 whatever but an open zooecial aperture, *n which consequently the orifice itself 

 represents the one, the operculum the other shell. 



Pall a s** suggests the view that the ooecia are ovaries, a view retained to the 

 time of Huxley. It was however chiefly the ocecia in the incrusting forms 

 (»£sc/iara*), which he was disposed to regard in this way, whereas on the other 

 hand he is more doubtful on the question, whether the free plant-like forms 

 ('CeUularia<i) are provided with such. »In plurimarum, presertim lapidescentium 

 Eschararum antiquioribus crustis passim, ad singularum cellularum oscula, obser- 

 vari solet bulla galeae instar cellulae ostio imminens, substantiae Escharae homo- 



' 12, p. 33—39. ^ 12, Introdviction p. IX. ' 12, p. 35. ' 12, Introduction p. XV. ^ 12, p. 71, 

 pi. XXIX, E. Ml, p. 36. 



