^jZrall, jlnTmo'"'] NOTES AKD MEMOKANDA. 47 



do not, in Dr. Hensen's view, appear to be precisely identified with 

 fibrillae, since he considers the fibrils of ordinary microscopical 

 description as being capable of further cleavage in a longitudinal 

 direction to an indefinite extent. He admits the correctness of the 

 usual statement, that when a fibril is examined it presents dark strisa 

 and an intervening substance ; but he maintains that this last is 

 traversed by a fine line, which he thinks is a discovery, though it was 

 long ago observed and described in this country by Carpenter and 

 others ; and he also divides the dark strias themselves into two halves, 

 between which is interposed a dull, finely granular disc, which he 

 calls the median disc. Thus the fibril would be composed of the 

 following laminfe : first, one-half of a dark stria ; secondly, the median 

 disc ; thirdly, the other half of the dark stria ; fourthly, the inter- 

 mediate substance, which is itself divided by a dark line. 



The Auditory Organs of Fresh-water 3Iollusl-s. — Some interesting 

 points in the microscopy of these structures are to be found in a paper 

 by Professor Gulliver in the ' Journal of Anatomy,' vol. iv. The 

 paper has been forwarded to us by the author. 



The Gregarina gigantea of the Lobster. — In the number of the 

 'Bulletins of the Eoyal Academy of Belgium,' just issued (No. 11, 

 1869), M. Edouard Van Bencden gives a long account, with a plate, 

 of the anatomy and development of the above Gregarina. M. Schwann, 

 who reported on the paper, speaks of it in the very highest terms, and 

 in accordance with the theory which he originated, and to which he 

 still adheres, regards the animal as a monster cell. The species is a 

 new one and has been given the above name by the author, who agrees 

 with Kolliker and Schwann in looking on it as a unicellular animal. 

 The author docs not add many histological facts to those already 

 pointed out by Mr. Kay Lankester and Mr. Leidy, but he gives a very 

 interesting description of the movements of the animal. He found 

 twenty-five of these parasites in the intestines of a single lobster. He 

 points out that the relation of the amcebiform bodies to the encysted 

 psorosperms is yet undetermined. 



NOTES AND MEMOKANDA. 



Improved Spring Clip. — Mr. W. P. Marshall sends us the fol- 

 lowing account of a clip which he has devised. We have seen a spe- 

 cimen, and consider it useful. In this form of wire clip for holding 

 down the cover glass during the preparation of an object, my inten- 

 tion has been to admit of readily examining an object in the micro- 

 scope with the clip on, without risk of the clip getting shifted and 

 displacing the cover glass. The clip is put on at one end of the slide, 

 and confined to a straight line along the middle of the slide ; the 

 lower half that clips on the slide reaches half-way to centre, and the 

 wire is then bent back again to the end ; and the upper half of the 

 clip is carried up in a bow, the end being curved down to press upon 



