( 489 ) 

 SUMMARY 



OP CUKKENT BESEABCHES RELATING TO 



ZOOLOGY AND BOTANY 



(principally Invertehrata and Cryptogamia^, 



MICROSCOPY, &c., 



INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS. 



ZOOLOGY. 



A. VERTEBBATA :— Embryology, Histology, and General. 



a. Embryology.t 



Uterus and Embryo.l — Mr. C. S. Minot has investigated the relations 

 of the uterus and embryo in the Eabbit and in Man. In the resting 

 uterus of the rabbit there are six longitudinal folds ; the orum attaches 

 itself on or between the two folds nearest the mesentery, and the placenta 

 is then developed ; the two adjacent lateral folds form a cushion (" peri- 

 placenta ") about the placenta, but the two folds opposite the mesentery are 

 flattened out by the stretching of the walls to form the swelling to contain 

 the embryo ; they constitute the ob-placenta. The entire epithelium 

 lining the uterine swelling degenerates, and this degeneration affects the 

 glands also. The connective tissue increases by hyperplasia in the pei-i- 

 placenta and to a greater degree in the placenta, and is transformed for 

 the most part into uninucleate perivascular decidual cells, but also in 

 part into large multinucleate cells. In the placental region the glands 

 are preserved as irregular anastomosing rows of coarse granular matter ; 

 below the glands is a zone containing wide vessels and large multi- 

 nucleate cells. 



The embryo is attached at first to the surface of the placenta only 

 by the ectoderm, with which the mesoderm soon becomes connected. So 

 soon as the coelomatic fissure appears we can speak of a foetal chorion 

 adhering to the placenta. When the allantois grows out it forms the 

 stalk of connection between the embryo and the placental chorion. 

 Outgrowths of the chorion penetrate the glandular layer of the placenta. 

 The coelom of the embryo does not extend to the edge of the placenta 

 next the peri-placenta, but the mesoderm does and is covered by 

 ectoderm. 



In the ob-placenta degeneration and resorption afiect only the 

 surface epithelium and the upper part of the glands ; the deep portions 



* The Society are not intended to be denoted by the editorial " we," and they do 

 not hold themselves responsible for the views of the authors of the papers noted, 

 nor for any claim to novelty or otherwise made by them. The object of this part of 

 the Journal is to present a summary of the papers as actualli/ puhlisltecl, and to 

 describe and illustrate Instruments, Apparatus, &c., which are either new or have 

 not been previously described in this country. 



t This section includes not only papers relating to Embryology properly so called, 

 but also those dealing with Evolution, Development, and Reproduction, and allied 

 subjects. X Journal of Morphology, ii. (1889) pp. 341-4G2 (4 pis.). 



