160 Royal Society : — Mr. Toynbee on certain 



when a ray of common light is incident, at any angle, upon the 

 polished surface of a transparent body, the whole of the reflected pencil 

 suffers a physical change, bringing it more or less into a state of 

 complete polarization, in virtue of which change its planes of polari- 

 zation are more or less turned into the plane of reflexion ; while 

 the whole of the refracted pencil has suffered a similar, but opposite 

 change, in virtue of which its planes of polarization are turned more 

 or less into a plane perpendicular to the plane of reflexion. 



The author then enters into a theoretical investigation of the sub- 

 ject, and concludes by pointing out a few of the numerous applica- 

 tions of his theory. 



2. Continuation of the paper of which the reading commenced 

 at the last Meeting, and entitled, " Researches tending to prove the 

 Non- vascularity of certain Animal Tissues, and to demonstrate the 

 peculiar uniform mode of their Organization and Nutrition." By 

 Joseph Toynbee, Esq. Communicated by Sir Benjamin C. Brodie, 

 Bart., F.R.S. 



In the introduction to this paper, the author first speaks of the 

 process of nutrition in the animal tissues which are pervaded by 

 ramifications of blood-vessels ; pointing out the circumstance, that 

 even in them there is a considerable extent of tissue which is nou- 

 rished without being in contact with blood-vessels. The knowledge 

 of this fact leads us to the study of the process of nutrition in the 

 non-vascular tissues ; which tissues he divides into the three fol- 

 lowing classes ; namely, first, those comprehending articular carti- 

 lage, and the cartilage of the different classes of fibro- cartilage. 

 Under the second head he comprises the cornea, the crystalline 

 lens, and the vitreous humour ; and, under the third, he arranges 

 the epidermoid appendages ; viz. the epithelium, the epidermis, nails 

 and claws, hoofs, hair and bristles, feathers, horn and teeth. 



The author then proceeds to show that the due action of the 

 organs, into the composition of which these tissues enter, is incom- 

 patible with their vascularity. In proof of the non-existence of 

 blood-vessels in these tissues, he states that he has demonstrated, by 

 means of injections, that the arteries, which previous anatomists had 

 supposed to penetrate into their substance, either as serous vessels, 

 or as red-blood vessels too minute for injection, actually terminate in 

 veins before reaching them ; lie also shows that around these non- 

 vascular tissues there are numerous vascular convolutions, large 

 dilatations and intricate plexuses of blood-vessels, the object of which 

 he believes to be to arrest the progress of the blood, and to allow a 

 large quantity of it to circulate slowly around these tissues, so that 

 its nutrient liquor may penetrate into and be diffused through them. 

 The author states that all the non-vascular tissues have an analo- 

 gous structure, and that they are composed of corpuscles, to which 

 he is induced to ascribe the performance of the very important func- 

 tions in the process of their nutrition, of circulating throughout, and 

 perhaps of changing the nature of the nutrient fluid which is brought 

 by blood-vessels to their circumference. The author then brings 

 forward facts in proof of the active and vital properties of these cor- 



