126 NATURAL SCIENCE [August 



deposit of calcareous tissue takes place between the basal ectoderm 

 and the surface of attachment, and that it is secreted by, not formed 

 within the ectoderm cells. These statements are confirmed by H. V. 

 Wilson for Manicina areolata, and in a question of this sort it requires 

 very strong evidence to upset the proofs from embryology. Miss 

 Ogilvie's evidence is hardly strong enough ; the appearances which 

 she describes are not unfamiliar to students of corals and are suscep- 

 tible of a different interpretation, but she has at least reopened the 

 question, which will have to be settled on better evidence than that 

 which she has adduced. 



Amongst the many figures which illustrate the work there are 

 several showing the relations of hard and soft parts in recent corals. 

 Some of them are correct, others are misleading, if not positively 

 incorrect. Take, for instance, the diagram of Turbinaria on p. 209. 

 The anatomy of this genus has been thoroughly described by Dr 

 Fowler, and we learn from him that there is a system of canals which 

 permeate the corallum and communicate with the polyp cavities. 

 These canals anastomose freely, but Miss Ogilvie's figure shows only 

 a few digitate or branched diverticula ; no anastomoses, no network, 

 and no transverse communications with the polyp cavities. The 

 figure of Fungia on p. 169 can only be called a diagram of theoretical 

 relations. As a matter of fact the soft parts of Fungia have not the 

 structure shown in the figure. Miss Ouilvie homolosnses the tissues 

 on the aboral face of Fungia with the edge-zone of other corals. This 

 is right enough, but it is not right to assume, as she does, that there 

 is no communication between the synapticula and through the theca 

 between the cavity of the edge-zone and the general cavity of the 

 body. As a matter of fact definite canals pass between the synapticula, 

 some are united below the level of the synapticula by a radial canal, 

 some are directly continuous with the cavities of the edge-zone. The 

 mesenteries are best developed above the synapticula, but some extend 

 also between and even below them, the rule being that the mesenteries 

 are attached to synapticula, either above or at their sides, but some 

 extend far down and send narrow mesogloeal bands to be attached to 

 the basal wall of the disc. Other features, such as the position of 

 the tentacles, are not correctly represented. The writer has the more 

 confidence in making these statements since he has recently examined 

 the anatomy of Fungia, in order to test the correctness of this figure. 

 One is inclined to suspect that Miss Ogilvie, whilst making plentiful 

 use of the anatomical researches of other authors, has not herself any 

 great familiarity with the structure of coral polyps. There is some 

 internal evidence that, after deciding in her own mind how the 

 corallum was formed, she has inferred the anatomy of the polyps from 

 the microscopical characters of their coralla, without studying the 

 actual relations in a sufficient number of instances. Such inferences 

 are apt to be misleading. Whether this is the case or not, Miss 

 Ogilvie has been led by her views on the formation of calcareous 

 tissue to give a lively but an unlikely accotmt of madreporarian 

 development and evolution, an account which is in harmony with the 

 figures criticised above, but which does not and cannot explain the 

 diagnostic character of the Madreporaria Perforata of M. Edwards and 

 Hainie — viz. the presence of a complex canalicular system in the wall, 



