y«/j/24, 1879] 



NATURE 



299 



fillings of canals in -which the Eozoon sarcode extended 

 through the calcareous intermediary matter. 



Dr. Carpenter represents this view of the different 

 parts of Eozoon by a systematic drawing, which we give 

 in Fig. 15. K, K, K are two rows of 

 chambers filled with serpentine. The 

 narrow parts between the chambers 

 correspond to the round passages of 

 foraminifera. In the lower row of 

 chambers, at G, the communicating 

 passage between two chambers is 

 divided into three narrow ducts by two 

 plates which lie embedded here. P, P 

 represent the walls of the chambers 

 penetrated by the fine pore-canals, in 

 the places of which in the real Eozoon 

 fibres of chrysotile are now situated. 

 Z, Z is the intermediary matter of 

 the Eozoon shell, into which the rami- 

 fied canals (St) (the present stems 

 of the Eozoon) are protruding. To- 

 wards the left, at g, a chamber duct 

 is represented, which unites two 

 chambers of different rows or layers. 

 Chamber ducts of this kind occur in 

 Tinoporus baailattis (Fig. 12), for in- 

 stance, and also in other living fora- 

 minifera. 



Prof. Moebiusthen proceeds to com- 

 pare one by one the different parts of 

 Eozoon with those parts of forami- 

 nifera to which, according to the views 

 of Dawson and Carpenter, they are supposed to cor- 

 respond. 



I. If the patches of serpentine are the filling materials 

 of the Eozoon chambers, then they represent their cavities 

 plastically in a similar way, as the 

 stone kernels of echini, gasteropoda, and 

 ammonites represent the interior cavi- 

 ties of the shells of these animals. 



The relative sizes of the serpentine 

 patches vary very much. The longi- 

 tudinal axes of the largest ones are 

 about thirty times as large as those of 

 the smallest. Their absolute sizes vary 

 from a few millimetres in length and 

 o"5 mm. in height, to 20-30 mm. in 

 length and 5-10 mm. in height. 



The serpentine patches of Eozoon 

 are in form and arrangement, as well 

 as in relative size, very unlike the 

 chambers of most foraminifera. In 

 their shapes none of the fundamental 

 forms arc reproduced again and again, 

 which in all the chambers of a fora- 

 minifera species point back to one and 

 the same law of formation. Neither 

 the fundamental shape of a ball or 

 lentil, nor the shape of a crescent or 

 sickle, which occur in the different fora- 

 minifera species, form the basis of the 

 serpentine patches of Eozoon. Yet 

 there is a certain regularity in their 

 shape and arrangement. Frequently 

 they have contours similar to crystals 

 of olivine (Fig. 10). Generally they 

 form concavo-convex layers which are 

 superposed and are separated by layers 

 of limestone (Fig. i). In many pieces 

 an increase in size of adjacent ser- 

 pentine patches in one direction may be observed. In 

 many others ball-shaped or oval serpentine patches 

 are arranged in such a manner that they form a spiral 

 (Figs. 3 and 4). But this arrangement does not give the 



impression of a getietic succession, as is the case with the 

 cham'^ers of spiral foraminifera. 



2. The fibres, forming band-like spaces between the 

 serpentine and the limestone are supposed to be the 



K 



\ I 



Fig. 17. 



siliceous fiUings of fine pore-canals which penetrated the- 

 calcareous chamber-walls of the Eozoon shell. 



The pore-canals in the chamber-walls of foraminifera 

 are cylindrical tubes, separated by calcareous intermediary 



Fig. 18. 



matter. Thus every tube runs isolated through the 

 chamber-wall (Figs. 12, 13, and 14)- The fibres of the 

 Eozoon, however, are prismatic needles or little plates^ 

 which are situated close together (Figs. 10 and 11), and 



