INVEBTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 923 



notwithstanding the generally received opinion, the smooth muscular 

 fibres are made up of fibrillae. The parts which have been made the 

 subject of his investigations are the stomach, intestinal canal, bladder, 

 and arteries of rabbits, pigeons, tritons, and frogs, together with various 

 organs from invertebrate animals. 



The size of the fibrillse appears to be fairly constant, and their 

 width to be very much that of the fibrillae of striated muscular fibre. 

 They are generally cylindrical in form and non-ramified ; in some 

 abnormal cases they exhibit varicosities. They are always optically 

 homogeneous, and very markedly exhibit double refraction. Each 

 fibrilla is surrounded by a layer of homogeneous matter, not doubly 

 refractive, and, during life, scarcely measurable. It would seem to be 

 soft and more or less coherent. In most cases the fibrils are set at equal 

 distances from one another, and are not grouped into fasciculi ; they 

 have, as a rule, a direction parallel to that of the long axis of the muscle 

 cells. There are, however, certain very remarkable exceptions to this 

 rule to be observed in many Invertebrata. In some the fibrils exhibit 

 a helicoid arrangement around the longitudinal axis of the cells. 

 Observations on this point can easily be made on the anterior adductor 

 muscles of Anodon, and it will then be seen that the angle which 

 these fibrils make with the axis depends largely on the state of con- 

 traction of the muscle. "When in a state of contraction they exhibit the 

 double striation which was first observed by Schwalbe. The author 

 shows that this is partly due to an optical illusion, and in part to the 

 state of compression of the fibrils. It is not, consequently, correct to 

 regard these muscles as affording any intermediation between smooth 

 and striated muscular elements. 



A very remarkable fact has also been noted by Engehnann — the 

 optic axis of the doubly refractive fibrils does not coincide with their 

 longitudinal axis, but with that of the cell. 



In conclusion, attention is directed to the generalization that there 

 is a unity in the structure of the different contractile elements ; these 

 arc, strictly, always fibrils. It is demonstrable already in the case of 

 muscles, whether " smooth " or " striated," as well as in that of vibra- 

 tile cilia and of spermatozoa. Further observations will probably 

 show it to be true of many foi-ms of protoplasm. 



Changes which Starch undergoes in the Animal Organism.* — 

 Hcrr H. E. Bimmermanu, alter referring to the statement of Musculus 

 and Gruber, that starch, by the action of diastase or acids, yields 

 soluble starch, maltose, grape-sugar, and three forms of dextrin, named 

 respectively a, ft, and y achroodextriu, which are variously affected by 

 ferments, states that wliile maltose and grape-sugar are produced by 

 the action of saliva on starch, glycogen, whether obtained on a diet of 

 grape-sugar or albuminoids, when treated in the same manner, yields 

 larger quantities of maltose and gi-ape-sugar and a reducible dextrin. 



Sachsse's method of estimating sugar by mercuric iodide was used, 

 as it was found difficult to determine the end of the reaction with 

 Fehling's solution. The substances were injected into the jugular 



♦ ' riliijrer'a Arohiv,' xx. (1880) pp. '201-10. Sco 'Journ. Chcin. Soc.,' 

 Abstr. xxxviii. (18S0) p. G77. 



