DR. BEALE, ON THE TISSUES. 257 



existence^ as would be supposed, give rise to the formation of 

 the most terrible and uncontrollable of morbid growths. An 

 irregular growth of a part of the secreting structure with the 

 vessels, for instance, of the liver, kidney, mamma, sweat-glands, 

 &c., may lead to the formation of a very soft, spongy, and 

 highly vascular growth, which will attain a very large size, 

 and appropriate the nutrient material which properly belongs 

 to other textures. After a time, perhaps, it reaches the sur- 

 face of the body, and fatal haemorrhage may take place from 

 its superficial vessels. In many such morbid growths we can 

 distinguish the elementary parts which have descended from 

 those taking part in secretion, although they have become 

 much modified, from the elementary parts which are connected 

 with the vessels prolonged into the structure. The former 

 constitute the " cells,'^ or " cellular elements " of the morbid 

 growth, and the latter, with the vessels themselves, form the 

 " matrix " or walls of the areolae or spaces in which the cells 

 lie. 



When we consider what a very slight derangement of the 

 elementary parts at an early period of development would 

 infallibly lead to the suppression or exaggeration of normal 

 structures, which are their direct lineal descendants, is it not 

 wonderful that morbid growths (irregular growth of one 

 or more tissues) or monstrosities (exaggeration or suppression 

 of series of elementary parts from which numerous different 

 tissues, entire organs, or limbs, are produced) are not of yet 

 more frequent occurrence than they are ? 



Many healthy structures may be removed from the 

 part of the body where they have been developed to a 

 distant part, and will nevertheless grow there. Skin, hair, 

 teeth, and other tissues, have been successfully transplanted, 

 but perhaps the most interesting, and not the least useful, 

 instance of this kind which could be adduced is the trans- 

 plantation of growing bone. M. Oilier has removed a por- 

 tion of the periosteum from a bone, and planted it in a dis- 

 tant part of the body — under the skin, for instance — and 

 bony tissue has been produced. The periosteum contains 

 bone-germs, which only require nutrient material to undergo 

 development into ordinary bone. The practical surgeon will, 

 of course, soon apply so important a discovery to the treat- 

 ment of certain cases. Some textures retain their vitality 

 after they have been separated from the parts where they grew 

 for a much longer period of time, and have a much greater 

 power of resisting destructive agencies, than others. 



In some of the lower animals, so active is the tendency to 

 growth, and so strong the power of resisting what would seem 



