APPENDIX 319 



Dawn of Life" in 1875, I used the following 

 terms : — " To understand Archaeocyathus, let us 

 imagine an inverted cone of carbonate of lime from 

 an inch or two to a foot in length, with its point 

 planted in the mud in the bottom of the sea, while 

 its open cup extends upward into the clear water. 

 The lower part buried in the bottom is composed 

 of an irregular network of thick calcareous plates, 

 enclosing chambers communicating with one another. 

 Above this, where the cup expands, its walls are 

 made up of inner and outer plates, perforated with 

 numerous round pores in vertical rows, and con- 

 nected with each other by vertical partitions also 

 perforated, so as to establish a free communication 

 of the enclosed radiating chambers with each other, 

 as well as with the water within and without. Such 

 a structure might no doubt serve as a skeleton for a 

 coral of somewhat peculiar internal structure, but it 

 might just as well accommodate a protozoan with 

 chambers for its sarcode, and pores for emission of 

 pseudopods, both outwardly and by means of the 

 interior cup, which in that case would represent a 

 funnel like that of Carpenteria, or one of the tubes 

 of Eozoon." 



On the whole, when we consider the magnitude 



