THE SAHVAET AND OTHER GLANDS OP THE COLUBEID^. 523 



mammalia *. It is also a noticeable feature that in those animals 

 in which this mixed type of structure is most marked, whether 

 it is in the parotid or in the submaxillary gland, the mucous 

 alveoli are restricted to one large or many small distinct lobules 

 close to the exit of the duct. 



The following stains were found useful in making preparations 

 of this gland : — borax carmine, alum carmine, Ehrlich-Biondi, 

 hsematoxylin and safranin, safranin and orange, eosin and 

 dahlia, carmine alum and bleu de Lyon, and fuchsin and bleu de 

 Lyon. 



The Earderian Gland. — This gland is developed to a large 

 degree in most snakes and is the most inconstant of all the 

 glands of the head in the extent of its development, since it 

 varies from the coudition of a mere strip of glandular tissue 

 present in Dryophis to that of the bulky gland of Homalopsis, 

 Enhydris, or Flaturus. In all the snakes examined it has been 

 found to be a typical albuminous gland with much smaller 

 alveoli than those of the parotid. 



The SuhUngual Gland f. — Immediately beneath the posterior 

 part of the sheath of the tongue is a large gland which pours its 

 secretion into the sheath of the latter structure, thus acting as 

 an accessory (lubricating) agent to facilitate rapid protrusion. 

 I can find but one previous mention of this gland, and 

 that by Minot+, wbo remarks: — "Underneath the sheath is 

 a very large gland, whicb I have seen in Eutania only. I 

 overlooked it at first and cannot therefore say whether it occurs 

 in Ancistrodon or Crotalus. As far as I am aware no similar 

 glands have been previously noticed in the Ophidia." I have 

 noticed it in Philodryas Schottii and Bipsas ceylonensis, and it is 

 most probably present in many other snakes, having, as Minot 

 remarks, been overlooked in the past. 



* N. Loewenthal, "Zur Kenntnis der Glandula submaxillaris einiger Sauge- 

 tiere," Anafc. Anzeiger, Band ix. (1894) p. 223. 



t Professor Howes has called my attention to the fact that Bisogni has 

 recently described as occurring in non-venomous snakes (Anat. Anz. Bd. xiii. 

 Nr. 18), a ' sous-lingual' glandular group consisting of three glands ; these do not 

 appear to me, however, to have any relation with the sublingual gland under 

 consideration. 



Cfr. also Bisogni, " Persistenza di una nuova glandula nel genere Vipera," 

 Anat. Anzeig. Bd. xiii. Nr. 18 (June 1897). 



I 0. S. Minot, " Studies on the Tongue of Reptiles and Birds," Anniv. Mem. 

 Bost. Soc. Nat. Hist. 1880. 



