I 



VIRGULAUIA MIHABILIS. 59 



various points of their length. In some {cf. Fif». 1) it occurs above 

 the largest leaves, in others some way below them, and in others again 

 about the position of the largest leaves ; i.e., the widest part of the 

 rachis. This variability is certainly not what we should expect were 

 the truncation due to death from natural causes. Thirdly, even 

 though it were true that the polypes after living a certain time 

 died and withered away at the top of the rachis, tlu>f tcould not 

 account for the stem beinq invariahlij broken off at tJie junction of livinrj 

 and dead poliipen. This stem contains, as we have seen, as much 

 as 85 per cent, of mineral matter, and it could hardly be maintained 

 that the death of the polypes encrusting it would so affect the stem as 

 to cause it to continually break off at the exact boundary line between 

 living and dead polypes. The fact that the stems are frequently 

 dredged up of dead specimens, from which the whole of the animal 

 matter has been removed by decomposition, and which stems are very 

 slightly if at all more brittle than stems of living specimens, proves conclu- 

 sively that death of the polypes would not in any way cause or account 

 for truncation of the stem as well. We are therefore compelled to 

 reject this explanation altogether ; firstly, because it has not been 

 proped to be a true cause, for we have no evidence at all that the top 

 does actually die down as suggested ; and, secondly, even if a true 

 cause, it is an insulificient one, because it leaves completely unexplained 

 the truncation of the stem as well as of the soft parts. 



If the cause of the truncation then does not lie in the Virgularia 

 itself, it must be some force acting on it from without. Fish or other 

 marine animals knocking up against the colonies, and so breaking 

 them off, could not account either for the invariable occurrence of the 

 truncation or for its situation, for lateral blows would tend to cause 

 fracture not high up the rachis, but, as already explained, at the point 

 of emergence from the ground ; i.e., junction of rachis and stalk. 



The only other explanation that occurred to us, and the one we 

 advanced when presenting our report to the Birmingham Natural 

 History Society on June 20th, is that the truncation is due to the tops 

 being habitually bitten or nibbled oft" as food by some marine animals, 

 most probably fish. At the time of presenting our report, this expla- 

 nation was offered as a pure hypothesis, in support of which we had 

 no direct evidence, and to which we were driven simply from inability 

 to conceive of any other that would satisfy the conditions of the 

 problem. Since this time we have been fortunate enough to obtain 

 direct evidence of a very striking aud satisfactory nature in support 

 of our view. 



Mr. R. D. Darbishire, of Manchester, to whom we mentioned the 

 difficulty, told us he remembered many years ago taking specimens of 

 Vir;iularia from the stomach of a haddock caught off Scarborough. 

 Fortunately these specimens, which bear the date of the 9th November, 

 1855, were preserved, and Mr. Dai'bishire has very kindly handed them 

 over to us for examination. Thev consist of five fragments of 



