334 GENERAL SUMMARY TO 



respiration. Hancock adds ('Phil. Trans.,' vol. 145, p. 835), that "to prove that the 

 brachial organs subserve the function of gills, as well as that of sustentation, it is only 

 necessary to refer to the manner in which the blood circles round the arms (labial 

 appendages) and is carried to the cirri ; but more particularly to its circulating through 

 these latter organs, and to its return direct from them to the heart." 



We have now referred to those portions of the animal that more nearly interest the 

 palaeontologist, as they leave their impressions on the internal surface of the valves of the 

 fossil. Numerous minute and accurate investigations have also been carried out by the 

 anatomist with respect to the other soft parts of the animal, but to which we can only 

 very briefly refer, as elaborate illustrations would be required in order to render their 

 details comprehensive to the general reader. We have, however, reproduced in PI. XXI, 

 of this volume Mr. Hancock's three best anatomical figures, showing in a very complete 

 and admirable manner the soft parts of the animal of Waldheimia australis, Bhynchonella 

 psittacea, and Lingula anatina, and to these the reader can refer. 



Brachiopoda in the adult condition have neither head nor brain, although Prof. Morse 

 thinks that he has recognised a hearing organ in Lingula. Eye-spots are likewise said 

 by several distinguished zoologists to be developed in all embryos of the animal, and that 

 they are to some extent sensible to light. The same was observed by Lucaze-Duthiers 

 in Thecidium ; for one day, while observing a number of live specimens in a large pail of 

 sea-water, several of them had their valves open, but on leaning, with all due precaution, 

 over the pail, and having interposed his head between them and the rays of the sun, 

 those in the shade instantly closed their valves. 



Forbes says in his ' British Mollusca ' (p. 340), that ocelli and otolitic vesicles are 

 certainly present in some species if not in all. The digestive organs, muscles, liver, &c, 

 occupy a small space only in the rostral portion of the shell, while the mantle and labial 

 appendages take up all the rest of its internal space. The digestive organs, liver, muscles, 

 &c, are partitioned off from the general cavity by a strong membrane, in the centre of 

 which is placed the animal's mouth ; the mouth conducts by a narrow oesophagus to a 

 simple stomach, which is surrounded by a t large greenish liver, and is divided into two 

 lobes situated one on each side of the alimentary canal. The digestive organ is minutely 

 described by Hancock at p. 814 of his admirable anatomical memoir already referred to. 1 

 In Waldheimia cranium he states the intestine to be short, terminating in a blind sac 

 before it reaches the perivisceral chamber ; and that the membrane lining the intestinal 

 tube of Wald. cranium is thick. In Bhynchonella the oesophagus, he says, is considerably 



1 It was at my urgent request and repeated solicitations that Mr. Albany Hancock undertook his 

 magnificent series of anatomical researches in connection with the Brachiopoda. The greater portion of 

 the material he worked upon was contributed by myself. I had also the great advantage of seeing 

 his admirable preparations during my repeated visits to Newcastle. These he minutely explained 

 to me in his usual liberal manner. For this splendid contribution to science Mr. A. Hancock was 

 awarded by the Royal Society one of its royal medals, a great honour which he had deservedly earned. 



