RfePOR* ON 'THE PENNATULliJA. 35 



action of the cells themselves. Watery or glycerine extracts of the 

 mesenterial filaments of Safiartia or Anthea are found to digest fibrin 

 rapidly at a temperature of 100 "^ -105" F. 



From the above account, which we have quoted because it is the 

 only one based on direct physiological experiments, and also because 

 it appears to be as yet but little known in this country, there can no 

 longer be any doubt as to the function of these hitherto mysterious 

 mesenterial filaments. 



ij. The lieproductive Ornun-t. The sexes among the PennatuUda are 

 distinct so far as is as yet known, the polypes of each individual Sea-pen 

 being either all male or all female.* Of the specimens of Funicidinn 

 obtained living at Oban the two larger ones, which alone have been 

 examined for the purpose, are both females, a circumstance we much 

 regret, inasmuch as no description of a male Funiculina has yet 

 appeared ; the statement that the sexes are distinct resting merely 

 on the analogy furnished by allied genera such as IlalUceptrum t and 

 Fenu/ittila.l and on the fact that in the female specimens describetl, «// 

 the polypes examined bore eggs. As we shall find when dealing with 

 the historical portion of our subject, only a very limited number of 

 specimens of Finiictilina have yet been examined with any care, so that 

 it is hardly safe to generalise concerning the apparent rarity of male 

 sjiecimens ; but it may well be that the male pens are eitlier really less 

 numerous than the female, or else that they are as a I'ule smaller, and 

 therefore disregarded. We trust that the Society will on some future 

 occasion be able to determine this point. 



The ovaries of Fioiicitlina (Figs. 10 and 15) are the free edges of 

 the six mesenteries which bear, higher up, the short mesenterial 

 filaments. The ova, or eggs (t), are developed as little prominences 

 attached by short stalks to the edges of the mesenteries, from which, 

 when ripe, they become detached, and then lie free in the body-cavity, 

 as shown in Fig. 10. 



Each ovum is apparently a single eudodermal cell, which becomes 

 bigger than its neighbours, and so projects above the surface of the 

 ovary : each is, from a very early period, enclosed in a thin 

 capsule, very similar in appearance and in behaviour with staining 

 fluids to the connective tissue mesodermal lamella of the mesentery ; 

 tliough whether it is actually developed from this lamella, as main- 

 tained by the Hertwigs § in the case of the Anemones, we have not 

 been able to determine. Later on each egg becomes invested by a 

 second outer capsule, which is much thicker than the first, is clearly 

 derived from the endoderm cells surrounding the ovuin, and contains 

 numerous minute pigment granules very similar in appearance to 

 surface, in the fully-developed egg, raised into a series of low ridges, 

 forming an irregular surface pattern. 



* Kolliker : Op. cit. 



+ Kolliker : Op. cit., pp. 147-17-2, and Plate XI., Fig. 95, Plate XII., Fig. W. 

 ; An account of the male Pennatula, of which no descriptiou has hitherto 

 been published, is given in the second part of this Keport. 

 § O. und 11. Hertwig : Op. cit. 



