ANATOMICAL DEFECTS OF THE NEW^-BORN. 



In tracing the history of the development of the embryo and 

 fetus, we have had occasion to remark the occurrence of devia- 

 tions from the normal course of development, which serve to 

 render the animal abnormal at the time of birth. In many of 

 these cases the aberration from the normal is so great as to cause 

 what are known as monstrosities, in which case the young ani- 

 mals are born so faultily developed that they usually perish im- 

 mediately, or if they live, the deformity renders them useless, 

 and they are consequently destroyed. The consideration of 

 these belongs to the domain of teratology, and, as such, are of 

 very great scientific interest. 



Quite frequently there exist, in new-born animals, various 

 deviations from the normal, insufficient to immediately com- 

 promise life, which may be spontaneously overcome, may be cur- 

 able by surgical procedure, or may persist, and the animal yet be 

 able to perform its functions without very great inconvenience. 



This group of minor deviations should be duly considered at 

 the time of the birth, and handled according to the outlook 

 for the ultimate value of the defective animal. It should be 

 determined whether, by any means, the defect can be over- 

 come, and to what extent its persistence will destroy the use- 

 fulness of the animal. If it is irremediable, and its persistence 

 destroys the value of the animal, it is highly important, in the 

 interests of economy, that the patient should be at once destroyed. 

 Still more important is the relation of these defects to the ques- 

 tion of hereditary transmission. The majority of them tend 

 strongly to become fixed as hereditary defects. Such animals 

 show a constant tendency to reproduce their own defects in their 

 progeny, even though artificially or spontaneously cured. Such 

 animals are consequently unsuitable for breeding purposes. 



These defects accordingly assume a highly important place in 

 the breeding of animals, whether viewed from the standpoint of 

 surgery or of zootechnics. 



I. Umbilic Hernia. 

 ExoMPHALUs. Omphalocele. Navel Hernia. 



Umbilic Heruia consists of the non-closure of the umbilic ring 

 in the abdominal floor, while the skin closes over the region in 

 1046 



