Evolution is conceptually based on cancer and its ability to metastasize (the transference of malignant cells from one area of the body to another).  Veins are added to the malignant areas to make them appear alive and growing just as cancer grows by the means of angiogenesis (the formation of new blood vessels to supply nourishment to a cancerous mass).  The cracked texture gives the vessel an appearance of dermal tissue, yet alive with a feeling of disintegration and internal shattering. Read more...