198 E - A - Schäfer, 



questions is wholly in favour of the pre-existence of muscle-columns 

 and of the presence of planes of separation between them, so that on 

 the main question, those which I have designated as belonging to 

 camp A must be adjudged to be in the right, there yet remain a 

 number of subsidiary questions which require to be answered. Assum- 

 ing the pre-existence of muscle -columns to be proved, it might yet 

 be affirmed that we have no evidence of the presence in the ordinary 

 muscles of any material such as the alleged sarcoplasm between them. 

 For the longitudinal lines which are seen may be merely due to the 

 juxtaposed surfaces of the muscle-columns, which are probably bounded 

 like those of the wing-muscles (subsequently to be described) by a delicate 

 membrane. The answer to this allegation is to be found in the fact 

 that sometimes in the ordinary muscles (e. g., grasshopper, Fig. 3) 

 always in the wing-muscles, and to a remarkable extent in the fin- 

 muscles of Hippocampus 1 ), the sarcoplasm is in considerable amount 

 between all parts of the sarcostyles, and it may reasonably be inferred 

 that it is always present normally, although it may be so to a rela- 

 tively slight degree. 



It might further be possible, the presence of inter-columnar sub- 

 stance or sarcoplasm being taken as proved, that a reticulum of the 

 kind which has been described might nevertheless be also present 

 imbedded in the sarcoplasm and and staining more decidedly than that 

 material with chloride of gold. This possibility, so far as I know, 

 has not been considered, or at least has not been put to the test, by 

 any authors who have written upon the structure of muscle. 2 ) Never- 

 theless, it is perfectly conceivable that this might be the case, and 

 that the different accounts which have been given of the structure of 

 muscle might be reconciled by supposing that the various writers have 

 been led to take one or other view of the matter, according to the 

 degree to winch one or other part of the combined structure was 

 accentuated in their preparations or perhaps in their thoughts. The 



*) Rollett, Arch. f. mikr. Anat. Bd. 34. 



-) Kölliker (op. cit. p. 7 05) speaks of the longitudinal lines seen in acid- and 

 gold-muscle as being „someAvhat firmer parts of the sarcoplasm", but adduces no 

 evidence in favour of this supposition. 



