REFLEX SECRETION OF SALIVA. 489 
submaxillary saliva. And it happens that the ducts with striated 
epithelium are very scanty in the sublingual gland, whilst they are 
numerous in the submaxillary gland. 
Keflex Secretion of Saliva in Normal and in other 
Conditions. 
In man, more complete observations have been made on the flow 
of saliva from the parotid than on that from the submaxillary gland, 
since the duet of the parotid is sometimes accidentally injured, so that 
the establishment of a parotid fistula becomes necessary. But some of 
the conditions of flow from either gland may be readily observed, when 
a cannula is simply placed in the opening of the duct of the gland into 
the mouth. 
In the dog, sheep, horse, and other animals, sometimes a permanent 
fistula, and sometimes a temporary fistula, of one or more of the glands 
is established. The observations have been made with and without the 
administration of anaesthetics. 
Ordinarily, between meals, the large salivary glands — except the 
parotid glands of ruminants — do not secrete. But as the mucous 
membrane of the mouth is constantly kept moist, saliva must constantly 
be formed by the smaller glands of the mucous membrane. In some 
animals the amount of this secretion is very considerable ; thus in the 
horse, during abstinence, 100 to 150 c.c, of saliva are, according to Colin, 1 
formed in an hour. Probably during sleep the amount diminishes. 
There is little doubt that this secretion is produced reflexly by conditions 
affecting the mucous membrane of the mouth, and a slight increase in 
the strength of the stimuli probably sets in action the larger glands also. 
In ruminants there are some peculiarities. The parotid gland se- 
cretes continuously (Colin, 1 Eckhard 2 ). The secretion is most abundant 
during feeding, rather less during rumination, and one-eighth to one- 
fourth the rumination rate during rest. 1 During rest, the submaxillary 
glands secrete little or not at all, and it is a remarkable fact that 
rumination does not, as a rule, cause any secretion from these glands, 
although it increases the secretion from the parotid gland, and although 
feeding causes a secretion from all the glands. 
Colin found in ruminants a slight continuous secretion from the sub- 
maxillary and sublingual glands during rest. Ellenberger and Hofmeister 3 
found none, but they noticed that there was occasionally a slight secretion 
from the submaxillary gland during rumination, and a more copious secretion 
during the act of drinking. According to these observers, there are occasional 
short pauses in the parotid secretion during rest. 
In ruminants, further, it has been said 4 that the secretion from the parotid 
gland continues after section of all the nerves running to it. In the ox, 
Moussu (1890) found that section of the buccal nerves diminished greatly, 
but did not quite stop, the parotid secretion. Eckhard (1893) states that 
section of these nerves does not affect the parotid secretion in the sheep ; he 
found about \\ c.c. to be secreted in ten minutes, whether the nerves were 
cut or no. The matter requires further investigation. 
1 Op. cit. 2 Ztschr. f. rat. Med.. 1867, Bd. xxix. S. 74. 
3 Arch. f. Anat. u. Physiol., Leipzig, 1887, Physiol. Abtli., Supp. Bd., S. 138. 
4 Centralbl. f. Physiol., Leipzig u. Wien, 1S93, S. 365. Cf. Schwann, Beitr. z. Anat. 
it. Physiol. {Eckhard), Giessen, Bd. vii. S. 170. 
