344 Eft'a Funk Muhse. 



sacs. It is merely the nature of the cells that has, as a rule, given 

 rise to this conclusion. Calmels and Seeck do not attribute the 

 expulsion to smooth muscle fibers about the individual glands. 

 Calmels does not describe or figure, as such, a layer of smooth muscle 

 fibers in the acinus wall. His statements regarding muscles are not 

 clear, and I shall not attempt to state his position. 



Seeck, on the other hand, describes the layer of spindle-shaped cells 

 in the gland wall, but definitely states that they are not muscular in 

 nature. According to him, the expulsion of the secretion is caused 

 l)y the subcutaneous muscles. Also that the attachment of the skin to 

 the underlying tissues differs according to the species, and thus the 

 secretion flows differently from the toad than from the salamander. 

 Further than this statement of Seeck's, those who have held that the 

 expulsion is due to the action of subcutaneous muscles have not stated 

 in what way they act. 



The skin in the toad is very loosely attached over much of the body. 

 While the glands are discharging, I have not been able to detect any 

 change in the tension of the skin. I have experimented with several 

 toads, the results of which prove beyond a doubt that the expulsion 

 of secretion from the glands is not due to the action of subcutaneous 

 muscles. Toads were killed by pithing, and no secretion was ex- 

 pelled. At once a long piece of skin, containing a parotid, was cut 

 on three sides, lifted and entirely freed, except at one end. Elec- 

 trical stimulus was then applied to either the upper or under side 

 of the parotid, and the secretion poured out in just the same way, 

 and just as freely, as in those animals where the stimulus was ap- 

 plied to the normal skin. 



Furthermore, there are present in the cutis of the skin of the toad 

 no smooth muscle fibers, other than those definitely arranged in the 

 acinus wall of the gland. 



It will be recalled that the collar of the outlet consists of two 

 zones of cells radially arranged, and that the cells of the inner 

 zone form a pad which rests upon the lumen, thus giving consider- 

 able diameter to the acinus in this region. Also that the more or 

 less continuous sheath of muscle fibers in the matrix of the acinus 

 is firmly attached to that part of the collar which rests against and 



