410 Harris Hawthorne Wilder 



parts are but slightly indicated and some of these rudiments can be 

 interpreted only through the dissection of such a specimen as Calori's 

 Iniops, in which these parts are better developed. For example, the 

 two halves into which the frontal bone becomes divided at the level of 

 the proboscis include between them a membraneous septum, Avhich ex- 

 pands at one point into a swollen nodule, Fig. 25 (a). This nodule 

 is lodged in a special cavity formed by the two frontal elements, as 

 though it were an important organ, but although its significance may 

 be evident to some of my readers, it seems to me wholly problematic. 

 There is no trace of olfactory fossae, crista galli, nasal septum or nasal 

 conchse. 



Tifpe 3. The Inner Eyes of Incomplete Diprosopi. 



I have been fortunate enough to secure two cases that illustrate this 

 type, representing different degrees of divergence. One of these is the 

 small pig embryo of Dr. Lambert (Teras I), the other is a pig at term 

 with two snouts (Teras XII), sent me by Dr. B. G. Wilder. In the 

 first of these the degree of separation is such that the two inner eyeballs 

 of the monster are in contact along their respective outer sides, yet 

 entirely distinct from each other; in the second the components of these 

 inner eyeballs form a single ball of abnormal width, which shows many 

 traces of its compound nature and, with its associated organs, exhibits 

 a perfect bilateral symmetry. For ease in interpretation the first of 

 these, the one with the separate eyeballs, is considered first. 



Case 1. (Teras I.) This specimen, undoubtedly the most valuable 

 in my entire collection, was received from Dr. Lambert perfectly pre- 

 served for microscopic study and, after a brief preliminary inspection, 

 was cut into a series of cross-sections. Its general appearance may be 

 learned from the accompanying sketch [Fig. 27 a], and, as I have no 

 sketch of the facial details of this double pig embryo, I add at the last 

 moment a sketch of the face of the double kitten embryo, just received 

 from Prof. B. G. Wilder. [Fig. 27 b.] This is a little more mature 

 than the pig embryo, as may be seen by the closed eyelids, but it repre- 

 sents about the same degree of duplicity and angle of divergence of the 

 two components. The mouths of the pig, however, were entirely dis- 

 tinct externally, but are confluent in the kitten specimen. If, in viewing 

 this sketch of the double kitten, the reader will cover alternately, first 

 one half and then the other, with a sheet of paper, he will have before 

 him two nearly normal embryonic faces, exactly alike. 



The total length of Teras I, the pig embryo, was 18-19 mm., and the 

 degree of development was the same as that shown by normal pig embryos 



