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Taenia elliptica 
beneath the cuticle, which he calls sub-cuticular muscles; an inner layer 
of longitudinal muscles, in bundles, lying outside a circular layer of 
muscles; and dorso-ventral muscles. He states that the circular and 
dorso-ventral muscles are connected at one point with the original cell 
from which they were formed, the fibre lying on the outside thereof. 
No cross or longitudinal striae were to be seen in the fibre of the dorso- 
ventral muscles which he claims branch at their ends and are inserted 
in the cuticle. He states such muscles are not known in any other 
Taenia except Bothrioceplialus. He further declares that no trace of 
the original cell is to be seen in the longitudinal muscles. 
Thus the description I have given for T. elliptica is in the main 
similar to Hamann’s account of T. lineata. the main points of difference 
being that he does not describe spiral contractions, concludes the dorso- 
ventral fibres are attached to the cuticle, and is apparently content to 
consider all the contractile fibres as muscles. It would at any rate 
appear probable these species are of very similar structure. 
The occurrence of spirally contractile fibres has been described in 
various animals and various organs. The stalk of Vorticella is of course 
the common example. Hertwig (1880) describes certain fixing or 
adhesive cells in the ectoderm of the Ctenophora, the base of which 
is prolonged into a spirally coiled thread. The threads also of the 
nematocysts of the Coelenterata are also coiled spirally in the cell. 
Spiral filaments have been described in Spermatozoa by various authors, 
amongst others by Ballowitz (1891, p. 217); while recently Nicholls 
(1909, p. 217) figures a cut Reissner’s fibre in the spinal cord of the 
lamprey, which has contracted spirally in a very marked manner. 
In none of these cases is the contractile fibre a muscle, while in all 
of them it may more reasonably be supposed to be some form of elastic 
tissue, and therefore, as Dendy (1909, p. 217) points out, of the nature 
of connective tissue. 
Schafer (1891, p. 241) discusses the origin of white and elastic fibres 
from connective tissue. I cannot claim I have evidence to show whether 
these contractile fibres in T. elliptica are formed by “ direct conversion 
of the protoplasm ” of the connective tissue cells, or “ by a deposit in 
the intercellular substance,” but if Fig. 2 gives any indication of the 
origin of these fibres it is certainly in favour of the former view, more 
especially when the relation of the fibre to the nucleus aud its 
surrounding protoplasm is taken into consideration. 
Thus there seems to be little doubt the so-called dorso-ventral and 
circular muscular fibres of T. elliptica are in reality white fibres, not 
