Miscellaneous. 321 



are much longer, their extremities are broken, and it is difficult to 

 ascertain their length. 



As constituents of these fibres may be distinguished a contractile 

 substance remarkable for its intense coloration and its homogeneous 

 aspect, and a nucleus accompanied by a protoplasmic substance. 

 The existence of an enveloping membrane seems doubtful ; the 

 author thinks that in most cases there is none, and at the utmost 

 it is only at the level of the nucleus that one can detect a delicate 

 hyaline pellicle, which seems to keep the nucleus in contact with 

 the element to which it belongs ; but this rudimentary membrane 

 soon disappears in contact with the muscular substance. 



When these fibres are lamellar one margin is always thicker than 

 the other, their form being like that of a sword-blade with a straight 

 thick edge, while the thin edge is notched and furnished with 

 irregular processes. 



The contractile substance of these muscles is perfectly homo- 

 geneous, and in most cases it is impossible to discover transverse or 

 longitudinal strite. Some, however, present a peculiar aspect, 

 Avhich might seem to indicate a coarse transverse striation ; colour- 

 ing reagents, especially hsematoxyline, show alternate light and 

 dark segments, which give the fibre a banded rather than a striated 

 appearance ; and it is easy to see that these false striations represent 

 actual thickenings of the muscular substance, and must be regarded 

 as waves of contraction, having nothing in common with the trans- 

 verse striaB of the A.rthropoda and Vertebrata. In a Tubicolar 

 Annelid (Profula intestinum, Lam.), which is remarkable for the 

 dimensions and lamellar form of the longitudinal fibres of the poste- 

 rior region of the body, the author has, however, found a true stria- 

 tion, comparable by its fineness and regularity to that of the muscles of 

 Mammalia. This striation is manifested chiefly in the dark regions 

 of the fibre ; and while its general direction is transverse, it varies 

 according to the point examined, so that the striae may become more 

 or less oblique. The striaj appear to be grouped in areas in which 

 their direction varies more or less. They are very fine. 



The autlior thinks that this striation in Protula mtestinum is not 

 unique ; but he regards its occurrence here as particularly interesting, 

 as it is in relation to the rapidity of contraction which occurs in 

 Protula. 



The nucleus is oval and placed outside the mass of contractile 

 substance. The protoplasm surrounding^it is sometimes very abun- 

 dant and accompanies the muscular fibre through a great part of its 

 length ; but generally it is reduced to small granular masses which 

 surround the nucleus and form irregular ridges upon the edge of the 

 fibres. — Co7nptes liendus, March 14, 1887, p. 795. 



The Stigmata of the Scolopendrida?. By Dr. Erich Haase. 



The number and structure of the stigmata is of great importance 

 in the classification of the very uniform family of the Scolopendridse. 

 Thus Newport distinguished fissiform, cribriform, and so-called 



Ann. (& Mag. N. Hist. Ser. 5. Vol. xix. 22 



