312 The Philippine Journal of Science 1918 



specimens, often assumes great dimensions — equalling one-half the size of 

 the skull. This sac is filled with calcareous matter, which is connected 

 with the ear by ducts or canals. Professor Wiedersheim, who was the first 

 to describe this organ in detail, considers it an auxiliary to the auditory 

 apparatus, having as its object the perfecting of the sense of hearing in 

 the animals. These calcareous masses are popularly, but erroneously, be- 

 lieved to be the undeveloped eggs which the females are supposed to carry 

 about in a sort of pouch until they are deposited in some safe place for 

 hatching. 



While severing the spinal cord in the region of the medulla, 

 I was attracted by a grayish white substance that oozed from 

 the region of the neck. This substance soon became hard on 

 exposure to the air. This gland containing the milky substance 

 was constant in two species of the pregnant house lizards. 

 Under the microscope this milky substance was seen to be of 

 an amorphous nature when fresh, but on exposure to the air 

 small crystals were formed. In all probability these were crys- 

 tals of calcium carbonate. At first it was believed that this 

 calcium gland was present only in pregnant lizards and that 

 it probably bore a definite relation to the formation of the cal- 

 cium shell about the egg substance. However, the gland is pre- 

 sent both in the male and in the female, but there is an increased 

 functional activity during pregnancy. 



I am indebted to Mr. E. H. Taylor, of the Bureau of Science, 

 for the proper classification of the Philippine house lizards, for 

 much material given me, and for many specimens that were 

 loaned to me, for all of which I wish to express my appreciation. 



There are four common Philippine house lizards found in Ma- 

 nila: Cosmybotus platyurus, Hemidactylus frenatus, Peropus 

 mutilatus, and Hemidactylus luzonensis. The calcium gland is 

 found in only two of the above-named species, Cosmybotus platy- 

 urus and Peropus mutilatus. In Hemidactylus frenatus and 

 H. luzonensis no calcium is stored in the gland in the region of 

 the neck. However, in these two species a spongy reticulum 

 is found in the region of the neck, which will be described 

 more in detail in a subsequent paragraph. All four species are 

 ovoviviparous, the embryo developing to a length of more than 

 1 millimeter before the egg is laid. 



The calcium glands are found, one on each side of the neck, 

 lying immediately behind the opening of the external auditory 

 meatus. They are slightly oblong, the greatest diameter being 

 in an anteroposterior direction. Their position is semicircular, 

 the extremities reaching the anterior and posterior sides of the 

 neck (Plate II, fig. 1). The gland in the pregnant Cosmybotus 

 platyurus is much the largest, having an average anteroposterior 



