The Morphology of Cosmobia 401 



to study the cranial nerves, the determination of these muscles is largely 

 conjectural. A comparison with the previous case is therefore the only 

 guide we have, but as the components are here much nearer together, 

 the reduction of parts is greater and the comparison is rendered difficult. 

 It seems likely that if an investigator should study a large number of 

 c3'clops eyes, representing different degrees of reduction, he would become 

 able to identify the muscles in a given case with some degree of certainty, 

 even without the help of the innervation, but with two cases only, and 

 these far apart in the series, my interpretation can be no more than con- 

 jectural. 



As a starting point we may take the ventral aspect of the previous 

 case (Plate II. Fig. 2), and try to imagine what would be the result 

 of crowding the two eyeball components still nearer together. The 

 muscle first to suffer by this treatment would naturally be the double 

 inferior oblique, since it has but a precarious footing at best, and has 

 already lost its attachment to the eyeball. The double rectus inferior, 

 however, has two good insertions, and a farther crowding would probably 

 do no more than push these two insertions together and bring the two 

 muscles in contact in the form of a double band. In like manner the two 

 recti externi would become also approximated and form a second median 

 double band, probably lying above the other. This would bring the 

 conditions on the ventral side precisely as they are found in the case in 

 question, and would suggest a rational identification for the two muscular 

 bands thus situated (Plate II, Figs. 4 and 5). The next muscles in 

 order, proceeding outwards, would then be the obliqui superiores and the 

 recti superiores, perhaps the two muscles that are here placed laterally, 

 upon the outer sides of the double eyeball. Lastly comes the most super- 

 ficial muscle upon the dorsal side, which readily suggests the levator 

 palpebrse. As in the other case, and very likely in all cyclops eyes, the 

 recti interni are entirely wanting, and thus all the muscular elements are 

 accounted for. 



This comparison of two different cases of Cyclops eye, in which as 

 many different grades of separation are represented, suggests the value 

 of the comparative study of definite cosmobiotic features, as they present 

 themselves in different cases. This study of Comparative Teratology 

 rests upon principles similar to those of Onto- and Phylogenesis; in all 

 three the varying degrees of development in a part furnish a clue to its 

 identity under the various forms in which it presents itself. A series of 

 stages as presented by different cosmobiotic monsters does not differ in re- 



