Hicron-At.lkn and KaIiLAM) — SliiJfj of Verneuilina polystropliK. 1 fi3 



obscure, bill, tlic cuuvicUon grows alinosL diiily sLrongur LliuL Lbe biolugical 

 problems which confront us in Uie study of Ihe higher and highest organisms 

 must eventually lind their solutiim in llic study of the unicellular organism. 

 As Sir James Paget observed in liis " Lectures on Surgical Pathology," so 

 long ago as 1849, " if we are ever to escape from the obscurities and uncer- 

 tainties of our art, it must be througli the study of those highest laws of our 

 science wliich are expressed iu tlie simplest terms in the lives of the lowest 

 orders of creation." A remarkable lead in this direction is indicated in the 

 late E. A. Miiichin"s Presidential Address to Section D (Zoology) at the 

 British Association in 1915, " On the Evolution of the Cell," in which 

 " swan-song" he recorded the bases of the remarkable line of inquiry which 

 was cut short by his untimely death. It is not, we think, in any way 

 preposterous to suggest that as science arrives — as arrive it must — at a 

 clearer comprehension of the nucleus of the primordial cell, and of its 

 constituent chromidia, the origin of such phenomena as that which we are 

 discussing will be revealed." 



(v) Yet another form of variation to which insufficient attention has been 

 hitherto devoted is the occurrence, in numerous species of widely separated 

 genera, of tests which are either wholly or in part chitinous. It has been 

 generally accepted that the replacement of the normal calcareous test by a 

 chitinous investment is evidence of starved conditions of existence. But, 

 however true this may be in some cases, as where foraininifera have 

 extended into very brackish water, we are not prepared to accept this as a 

 general explanation of the existence of chitinous \ ariation. All the evidence 

 in our possession tends to show that in most, if not in all foraminifera, a 

 chitinous membrane, perfoiate or imperforate, according to the type, exists 

 between the protoplasmic body which it encloses and the external shell.-' 

 And this chitinous wall is subject to hypertrophy, perhaps atrophy, and all 

 the other variations wliich normally occur. Tests of Foraminifera, perfect 

 in all respects, but formed entirely of chitin, are not uncommon objects, and 

 one occasionally finds damaged individuals who have repaired their lesions 



■ * It may seem a startling and breathless generalization, but we would suggest, with 

 all due caution, that in the nuclear matter may be discovered the causa ainsans of such 

 phenomena, even to the rudiuieutary occurrence of the pituitary body, upon the condi- 

 tions of which the phenomena of gigantism and nanism would appear to depend. 



■■^' Mr. F. Chapman writes to us from Melbourne, in answer to our inquiry, that he 

 had identified "an undoubted chitinous lining" to the shells of SpiriUina gruumii, 

 Chapman, recorded by him from the Upper Cambrian of Malvern (Q.J. Geol. Soc, London, 

 vol. Ivi, p. 259, PI. XV, figs. 1, 10, and 11), and subsequently identified by us, as the 

 oldest existing specific form of life from Clare Island {loc. cit., note 7, p. 107, PI. ix, 

 figs. 2, 3). 



