On the structure of cross-striated muscle. 235 



Postscriptum. 



The above article was completely written and ready for publi- 

 cation six months ago but its issue has been delayed by difficulties 

 in the printing and engraving. Foreseeing the probability of this 

 delay I sent a preliminary note, embodying my observations on the 

 tubular structure of the sarcous elements of the wing-muscles, to the 

 Eoyal Society last December, together with a number of photographs 

 from preparations illustrating the principal points to which attention 

 was to be drawn. Shortly afterwards I forwarded to the Eoyal Society 

 a paper in which I drew a comparison between the structural and 

 contractile appearances of muscle and of amoeboid protoplasm. These 

 two papers, which have appeared in the Proceedings of the Eoyal 

 Society, are to be regarded as supplementary to the one which is here 

 published; and to them will be added a third, embodying photographic 

 observations of the leg-muscles, which I hope shortly to be in a 

 position to publish. 



I may also take tins opportunity of referring to the appearance, 

 since the above article was in type, of three communications upon the 

 subject of muscle-structure *). It is impossible tor me to criticize these 

 in the present article but I notice with satisfaction that with regard 

 to the structure of the ordinary muscles in general, and the nature 

 of the „accessory disks" in particular, the conclusions at which Eetzius 

 has independently arrived, are very similar to those which I have 

 above endeavoured to set forth 2 ). 

 April, 1891. 



mentioned by their titles. Of these, those by Kölliker, Brücke, Krause, Hensen and 

 Engelmann are so wellknown that a special reference is unnecessary to any who 

 are conversant with the subject. There have been of late so many lists of muscle- 

 literature, and particularly a very complete bibliography by van Gehuchten, that it 

 appears to me superfluous to add to the length of this article by a similar enumeration. 



*) G. Eetzius, Muskelfibrille und Sarcoplasma. Biologische Untersuchungen, 

 Neue Folge, I, 1890; J. B. Hay craft, On the minute structure of striped muscle, 

 with special allusion to a new method of investigation, by means of „impressions" 

 stamped in collodion. Proc. Roy. Soc, Jan. 1891; Bütschli und W. Schewiakoff, 

 Ueber den feineren Bau der quergestreiften Muskeln von Arthropoden. Vorläufige 

 Mitteilung. Biol. Centralbl., Bd. XI, No. 2, 1891. 



2 ) The history of the subject is also very concisely and clearly given in Eetzius' 

 article. 



