and Laboratory Methods. 2629 



CYTOLOGY, EMBRYOLOGY, 



AND 



MICROSCOPICAL METHODS. 



AGNES M. CLAYPOLE MOODY. 



Separates of Papers and Books on Animal Biology should be sent for Review to Agnes M. Claypole 

 Moody, 125 Belvedere Street, San Francisco, Cal. 



Beard, J. Embryology of Tumors. Anat. The author is applying his researches 

 Anz. 23: 18-19,486-494, 1903. ., J. , -1 ,• r ,, ^ ^, 



^ t n^n. y o Qj^ (-j^g distribution of germ-cells to the 



origin of these pathological growths. Tumors are shown to be referable to abnor- 

 mal attempts at development on the part of one or more vagrant or aberrant 

 primary germ-cells and also to the bizzare pathological manifestations by such of 

 some greater or less portion of the life cycle of normal development. The author's 

 researches have revealed the fundamentally impossible nature of three tenets 

 of modern embryology : somatic origin of germ-cells, direct development, epi- 

 genesis. Continuity of the germ-cell from generation to generation is now an 

 accepted fact. As these cells do not arise at the first division of the fertilized 

 ^gg but at a later definite period, there always are some cleavage products con- 

 cerned neither in the formation of the embryo nor of germ-cells. The products 

 give rise to an asexual foundation, larva, phorozoon upon which the germ-cells 

 and with these an embryo take origin. In human development this is the 

 chorion. The formation of an embryo is only a part of the life cycle. The set 

 of germ-cells is produced, each being a potential embryo. If two primary germ- 

 cells undergo normal development, identical twins result. If these should 

 develop together or at different times with abnormalities on the part of one, a 

 rudimentary embryo, an embryoma or a tumor may result. The primary germ- 

 cells are constant in number for a given species, 8 in frog, 32 in lamprey, 128 in 

 dog-fish. One deducted from the number to form an embryo leaves the remain- 

 der to wander into the embryonic body to form the reproductive products. Any 

 of these vagrant cells may fail to reach the normal position and thus by being 

 included in other organs and parts " infect " the whole body. Tumors form a 

 series of parasites comparable to the eulima series of snails parasitic on star-fish 

 and other echinoderms. A tumor is a more or less reduced incompletely differ- 

 entiated sterile metazoan organism. It is started from a vagrant germ-cell, and 

 owing to abnormal conditions develops part of its possibilities. "Hence they 

 are not/(7r/ of the organism in which they occur, but reduced sisters or brothers.'''' 



A. C. M. 



Bensley, R. R. Concerning the Glands of The author studied these glands in 

 Brunner. Anat. Anz. 23: 4q7-t;o7, iqci. , ^ • r i j 



^ -^ ^ -^ twenty species of mammals, and suc- 



ceeded in getting a modified muchematin stain that differentiated the double 

 nature of the glands in all cases. By increasing the given strength of the stain 

 solution with altering the proportion of the solid constituents, sections fastened 

 to the slide and in celloidin were well stained. The solution is prepared as 



