294 SUMMAEY OF CURRENT RESEARCHES RELATIKG TO 



gland are in the beginning usually lymph vessels. The reticulum cells 

 in their lumen appear only secondarily, and are descendants of the lymph 

 vessel endothelium. The special lymph-gland buds are from the be- 

 ginning onwards of different size. Some reach during intra-uterine life 

 their definite structure, others remain in a low stage of development. 

 The small, often microscopic glands which one finds in the adult are 

 rudimentary forms, which under special circumstances may develop 

 further, even in the adult. Owing to incomplete separation of the gland 

 centres, twin or other malformations of lymph glands arise. 



Origin of the Vitreous Humour.* — A. v. Szily finds in the early 

 stages of development thread-like fibrils, which are extensions of the 

 intercellular bridges of the cells of the adjacent epithelial layers. They 

 are connected with the protoplasm of the cells by means of a " skittle- 

 shaped" structure (Jcegelformigen), which resembles the "basal-skittles" 

 of the lens cells discovered by v. Lenhossek. If the fibres arise near 

 where mesenchyme cells are abundant, they unite secondarily with these, 

 the mesenchyme dominating the form ; in cell-free areas the fibres pre- 

 ponderate during the whole of life. Whether they belong genetically 

 to the retina or to the lens is an unimportant factor. Owing to the 

 independent development and subsequent union of these elements of the 

 vitreous humour, the products of the different germ layers cannot be 

 distinguished, so that no decision as to what is ectoderm and what 

 mesoderm can be arrived at. 



b. Histology. 



Zoological Distribution, Mitoses, and Transmissibility of Cancer.f 

 E. F. Bashford and J. A. Murray adduce evidence tending to show that 

 the wide zoological distribution, the character of the mitoses, and the 

 transmissibility of cancer, are nearly related phenomena with a common 

 basis. 



Malignant new growths have been found in a large and varied series 

 of animals, not only in domestic animals, but also in animals living in a 

 state of nature : wild mouse, codfish and gurnard. 



A complicated sequence of cell-changes has been found to be charac- 

 teristic of carcinoma and sarcoma alike. This sequence is the same as 

 that which initiates the origin of the sexual generation in plants from the 

 asexual, and is terminal in the history of the sexual cells in animals. It 

 must be noted, also, that all the cells of the malignant new growths do 

 not undergo the reducing division ; a certain number^ differentiate in 

 the direction of the tissue among which they have arisen, and in the 

 secondary growths when present ; somatic mitoses occur in the growing 

 margin, which is also a feature in the growth of cancer when transferred 

 to a new host. Cancer is an irregular and localised manifestation of a 

 process otherwise natural to the life-cycle of all organisms. Successful 

 transplantation experiments have been made, e.g. with mice, in which 

 malignant new growths were transferred from one animal to another of 

 the same species. 



* Anat. Anzeig., xxiv. (1903) pp. 417-28. 



f Proc. Roy. Soc. London, Ixxiii. (1904) pp. 66-76 (1 pi. and 8 figs). 



