THE ROLE OF GENES IN THE EPIGENETIC SYSTEM 343 



"Anomaly of cartilage" 



Narrowed lumen of 

 trachea 



Thickened ribs 



Fixation of thorax in 

 inspiration 



Slight changes in larynx 

 and nose 



Kyphosis Abnormal situs of 



thoracic viscera 



Spur on deltoid ridge of 

 humerus 



Slow suffocation Increased resistance General arrest Blocked nostrils 



in pulmonary of development 



circulation 



Coma exposure 

 inanition 



Compensatory 



hypertrophy of 



right ventricle 



of heart 



Blunt snout Inability to suckle 



Decompen- 

 sation 



Exitus 



Capillary Faulty occlusion 



haemorrhages of incisors 



into lungs 



Difficulties in 

 feeding 



Starvation 



V 

 Gxitus 



Y 

 Exitus 



Exitus 



Exitus 



Figure 15.6 



A gene in the rat causes abnormalities in the formation of cartilage. This 

 has many secondary consequences ('pleiotropic effects'). (After Gruene- 



berg 1938.) 



