April 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 889 



and are believed to be built up of still finer spiral tubes. 

 One of the two spirofibrilles in each spirospart serves for the 

 upward conduction, while the other serves for the downward 

 conduction of plastids, and the author says he has been even 

 successful in seeing the plastids move along the hollow spiro- 

 fibrilles. These plastid substances we are in the habit of 

 staining with our ordinary histological methods, the walls of 

 the spirals taking on no stain. Vacuoles are further believed 

 to correspond to enormously dilated spirofibrilles, and the 

 nucleus to be the meeting point of several spirosparts. 



I am as yet unable to criticise these views of Fayod, but 

 shall do so fully as soon as I have repeated the various 

 experiments described in this highly interesting paper. 

 Simply judging by the illustrations (figs. 1, 2, 3, 4), I would 

 be inclined to say that spirofibrilles exist, but certainly I 

 would not be able to construct from these four figures the 

 diagrams figs. 6 and 7. 



To return to fig. 48. External to the nuclear membrane 

 {3), two paranuclei {vi) have been figured as lying close to 

 one pole of the nucleus, and sending branches to the 

 nucleolar (j;), nuclear (o), and extranuclear {n) achromatin. 



Two paranuclei {m) have been figured, as according to 

 riemming* and Guignard,t two bodies are usually, if not 

 always, to be found in a resting cell. Each paranucleus con- 

 sists of a "central body" (v. Beneden), surrounded by a pale 

 area — the "attractive sphere" (v. Beneden) [Boveri's "centro- 

 some " and " archoplasm " respectively]. The " attractive 

 sphere " is represented as sending out filaments in all direc- 

 tions. ;|; The archoplasm of paranuclei does not consist, how- 

 ever, of a homogeneous mass, for Platnerg says that the 

 paranucleus of the resting spermatocytes of Helix ijomatia 



* W. Flemming, Neue Beitrage z. Keuntniss d. Zelle, in Arcliiv. f. Mikrosc. 

 Anat. xxxvii. p. 701. 



+ L. Guignard, Sur I'existeiice d. "spheres attactives " dans les cellules 

 vegetales, in Comptes Rend. Ac. d. sc. Paris, 9 Mars 1891. 



X The best stain for the centrosome is, according to Flemming (Arehiv. f. 

 Mikr. Anat. xxxvii. p. 686) orange G. [(the sodium salt of ani]in-azo-;3- 

 naphtal disulfosaure) Griibler]. Hermann (Arehiv. f. Mikr. Anat. xxxiv. and 

 xxxvii. pp. 571, 583) uses his platiuo-chlorid-osmo-acetic mixture, with sub- 

 sequent reduction of the osmium by wood-vinegar, or — a modification of Pal's 

 hsematoxylin. 



It was in sections stained with Kleinenberg's No. 1 haematoxylin, and 

 decolorised in bismarck-brown, that I first observed these bodies, three years 

 ago. 



§ Arehiv. f. Mikrosc. Anat. B. 26 and 33. 



