480 PEOP. B. C. A. WINDLE ON TERATOLO&IOAIi EVIDENCE 



Part 3. — Malformations possibly Mechanical. 



It will be most convenient to take this group under tlie head- 

 ings indicated in the first section. 



Clefts due to Tumours. — FcEtuses born with such deformities 

 are, I believe, almost always still-born. In any case I have 

 never met with an account of any case where such a condition 

 was hereditary. 



Clefts due to Fluids of an Infiammatory Nature. — As examples of 

 this may be mentioned such defects as abdominal fissure, sufi'erers 

 from which are always still-born ; aneucephaly again, a condition 

 in which life is impossible for more than a few hours at the 

 most ; with, possibly, spina bifida. Opinions are, however, 

 divided on this question. " Which is the primary defect," says 

 Mr. Treves *, '' arrest of development in the bones, or dropsy of 

 the membranes ? Does the deficiency in the bony canal en- 

 courage a protrusion of the membranes ? Or has the protrusion 

 prevented the proper formation of the osseous canal ? " To this 

 question, he says, no satisfactory answer has yet been given. 



Defects due to Formation of Inflammatory Fibrous Tissue. — 

 That part of this section which relates to deficiencies of extremi- 

 ties has already been sufficiently dealt with in the paragraphs on 

 Peromelia and Perodactyly, since most of what was there said in 

 connection with the influence of amniotic bands in the produc- 

 tion of defects might also be applied to bhe present question. 

 As far as atresia ani is concerned, if any cases are attributable 

 to the cause under consideration, that defect is of no importance 

 so far as this inquiry is concerned, since there is no evidence, so 

 far as I am aware, that it is ever hereditary. 



Defects due to Amniotic Pressure. — These defects are of a 

 totally difterent nature to those previously discussed in con- 

 nection with the amnion. The defects of this class are due to 

 the compressing action of an amnion free from obvious inflam- 

 mation or other disease. This pressure may follow, it appears, 

 from (1) a deficiency of liquor amnii, whereby the fcetus is 

 brought too much under the influence of the amnion and 

 possibly also of the uterine walls ; (2) a want of sufficient 

 growth on the part of the amnion itself, whereby the growing 

 embryo is compressed ; (3) possibly, the abnormal size of the 



* Internat. Encycl. of Surgery, vol. iv. p. 891. 



