474 
MR. BOWMAN ON THE MINUTE STRUCTURE AND 
Table, showing the variety in the proximity of the striae in dead muscle. The figures 
indicate the number of striae in tooo English inch. 
Number of observa- 
tions recorded. 
Maximum. 
Minimum. 
Mean. 
Greatest difference in same specimen. 
Human . . 27 
15*0 
60 
9*4< 
r 
Min. Max. 
Sterno-hyoid. 7‘5 12 - 75 
Sp. constrict, pharyng 6‘75 1U25 
(Esophagus 6'75 ll - 25 
Cremaster 90 150 
Rectus cruris 60 90 
Mammalia 15 
15-0 
6-7 
10-9 
' 
Diaphragm, Cat 7 - 5 150 
Rect. oculi, Horse 90 13 - 5 
Birds .... 7 
14-0 
70 
10-4 
Hen (Gallus domesticus, female) .. 70 llO 
Reptiles. . 7 
20-0 
6-7 
11-5 
Lizard 90 200 
Fish .... 20 
18-0 
7*5 
■ 
Skate ( Raia Batus ) 90 180 
Flying Fish ( Exocoetns volitans ) . . 90 150 
Insects . . 8 
16-0 
4-5 
9*5 
Blue Bottle Fly ( Musca vomitoria) 5 - 25 150 
Perhaps the most interesting conclusion deducible from the above Table, is the 
uniformity of the mean number of striae in a given space in the six divisions included 
in it. The next remarkable fact is, that in each division a great variety is observable 
in their number, not only in an average of all the examples examined, but in single 
specimens. And I may add, that this variety has been observed continually, both on 
contiguous fasciculi, and on the same fasciculus in different parts. I have not con- 
sidered it requisite to detail the particulars of each observation. 
Of the $arcole?nma, or Tunic of the Primitive Fasciculus. 
I now proceed to give some account of a structure entering into the compo- 
sition of all voluntary muscle, and which, though some imperfect notices of its 
existence are to be found in two or three authors, is not generally known, and has 
certainly never been demonstrated in that complete and definite manner which its 
importance seems to demand. I allude to a tubular membranaceous sheath of the 
most exquisite delicacy, investing every fasciculus from end to end, and isolating its 
fibrillse from all the surrounding structures. It is true that numerous writers have 
described a sheath to the primitive fasciculus ; but that by this term is merely intended 
a production of that general sheath of filamentous tissue which invests the whole 
muscle and its lacerti, might be shown by a crowd of quotations*. Other sheaths are 
indeed mentioned, such as that of Mandl'J-, said to contain the striae, and to be 
* For example, Leeuwenhoek, passim. Prochaska, De Carne Musculari, sect. i. cap. iii. Hildebrandt, 
Anatomic des Menschen von E. H. Weber, Band i. p. 388. Blainville, Cours de Physiologie, vol. ii. 1833, 
p. 311-14. Cruveilhier, Anat. Descriptive, tom. ii. p. 14. Mayo, Physiology, 3rd edit. p. 31. 
t Traite Pratique du Microscope, p. 75. 
