366 ELECTRO-PHYSIOLOGY CHAP. 



inclined to regard the whole of the developed plate as the 

 homologue of the motor end -plate only. Eeniak (I.e.) drew 

 attention to a peculiar and regularly arranged punctuation upon 

 the ventral surface of each electrical plate (as observed by all 

 later workers), which Boll (5) described many years later as a 

 new structural relation. This consists of a remarkably fine, 

 regular, and homogeneous punctuation, immediately subjacent 

 to the terminal network, viewed from below (Fig. 235). The 

 arrangement of dots corresponds perfectly with the configuration 

 of the terminal network, so that the little points follow the 

 reticulation of the net, and to some extent mark its distribution. 

 Several (23) irregular rows of clots correspond, for the most 

 part, to the single threads of the net, the number of points in 

 1 sq. mm. amounting, according to Krause and Iwanzoff, to about 

 a million. 



In optical cross-sections of the plate (at the bending-points) 

 the punctuation is seen to be the expression of a fine and regular 

 striation, vertical to the surface (cf. Fig. 231, ce), which extends 

 from the ventral side to the border of the first sixth of the 

 diameter of the plate (palisade border, Eanvier's cils elcctriques), 

 and was known to Eemak, who regarded the dots of the super- 

 ficial aspect as the bending-points of small cylinders arranged in 

 a palisade upon the surface. Krause in the main subscribed to 

 the same opinion, regarding the dots as " the optical expression 

 of small cylindrical rods, viewed from above, which belong to the 

 neurilemma, and form as it were ' nails,' riveting the flattened 

 terminal fibres." Boll, Eanvier, Ciaccio, and Trinchese viewed 

 them as the true, terminal nerve-endings. According to Iwanzoff 1 

 the palisade merely represents the processes of the structureless 

 membrane which clothes the lower surface of the electric plates, 

 corresponding with the sarcolemrna of the muscle-fibre. 



Fritsch, on the contrary, holds the dots (which look black 

 when treated with osmic acid, and examined under the highest 

 dry power, or a weaker immersion lens) to be " the optical ex- 

 pression of strongly refracting and closely approximated granules, 

 embedded in a less refractile, semi-fluid substance, which covers 

 the lower surface of the plate." Fritsch proposes to call this 

 layer, which has nothing to do with the true nerve-ending, the 

 xtrntmn yranulosii m. Its relation to the other layers of the 

 electric plate is most plainly seen in transverse section (Fig. 236). 



