PROGRESS OF MICROSCOPICAL SCIENCE. 155 



" In my original description of Calcarina * — the type to wLicli, as 

 regards the general distribution of its canal-system and its relation 

 to the intermediate skeleton, Eozoon has the closest resemblance — I 

 gave the following account of that relation (p. 554) : ' The proper 

 walls of the chambers are uniformly perforated, like those of the 

 chambers of Rotalice, by foramina of considerable size (averaging 

 above ^g^o^fth of an inch in diameter) ; with these the canals of the 

 supplemental [or intermediate] skeleton do not seem to be directly 

 continuous, for they are of about double the diameter and lie further 

 apart from one another ; but immediately round the proper walls of 

 the chambers there seem to be irregular lacunar spaces, into which the 

 foramina open externally, and from which the passages of the canal- 

 system originate,' Now, in my ' Supplemental Notes on the Structure 

 and Affinities of Eozoon canadense 'I I stated that precisely the same 

 relation is shown to exist in decalcified specimens of Eozoon, by the 

 implantation of the dendritic models of the chamber-casts in plates 

 formed by the coalescence of the aciculte that occupied the tubules of 

 the ' pi'oper wall.' Having now been fortunate enough to meet with a 

 transparent section wliich exhibits this relation most unmistakably 

 (see Fig. b b), 1 fearlessly ask the verdict of any Biologist familiar 

 with microscopic structure, whether any more exact realization could 

 be presented of the structure I had described in Calcarina, — allowance 

 being of course made for the different scale of the tubulation of the 

 ' pro2)er wall,' which is here Jine ' nummuline ' not coarse ' rotaline.' " 



We think the verdict of most microscoj^ists will be to the effect 

 that the structure is unquestionably one of organic origin. 



Metrogressive Changes in the Serous Layer of the Babbifs Ovum. — 

 Dr. Stirling says that Herr K. SlavjauskyJ describes the degenera- 

 tion, called by him reticular ("reticulare degeneration"), which tlie 

 epithelial cells of the serous layer of the ovum undergo in their phy- 

 siological development. During the development of the ovum, the 

 epithelial cells of the part of the serous layer lying close to the um- 

 bilical sac become thin and flat, and in the cells themselves some 

 transj)arent spots are to be observed. By-and-by the protoplasm dis- 

 aj)pears, and holes are observed in the cells. These holes gradually 

 enlarge, so that, at last, in place of the epithelial membrane there is 

 to be seen a reticulum of the remains of the protojilasm of the epithe- 

 lial cells, containing in some places the nuclei. There is thus esta- 

 blished a physiological prototyi:ie for the pathological degeneration of 

 the epithelium, described by Wagner under the name of fibrinous 

 degeneration, in cases of croup and diphtheria. — See also ' Medical 

 Eecord.' 



The Microscopic Blood-vessels of the Intestine. — In a note in the 

 ' Medical Kecord,' by Dr. Stirling, the writer says that Herr A. 

 Heller § arrives at the follomng results : — 1. Every villus contains an 

 artery which runs, as a general rule, to the point of the villus without 

 branching. In man only does it begin from the middle of the villus 



* Thil. Trans.,' 1860. t 'Proceed. Gcol. Soc.,' Jan. 10, 1866, p. 222. 



X Ludwig's ' Arbeiteu,' vol. vii. § Ibid. 



