138 



Devklopjiext oi" Sexual Okcjans ix CYMcrnxiASTEu. Kv ('. JI. Ek;enman'X^ 



[Abstract.] 



Kt^productivc colls are s('<i;rc'i>atoil verv early hefore any |initii\ crtebi';r are 

 formed, and the euihrvd is no more tiian .;> nun. in dianietei'. Aliont a dozen 

 cells are present at this early time. These migrate backward with tlie gi-owth of 

 the eml)ryo, but dn not siiare in the general develoi)ment. Winn the larva ha.s 

 attained a length of 7 mm. the cells Ijegin to divide, and l)y the time the larva has 

 reached a length of 8 mm. all have undergone division, so that about 24 cells are 

 present. These are arranged in a V shaped area. The arms are formed l)v the 

 folds in the peritoneum in which the sex cells lie. 



The sexes become difierentiated when the larva- have reached 10 mm. The 

 diflVrentiation becomes apparent in the general shape of the reproductive glands 

 before any diflference is noted in the rei)rodnctive cells. 



At 2U nun. the groni)ing of the cells has l)ecoine characteristic of the sexes. 



FoRMATiox oi' Ovariax Cavity. — The reprodnctive cells never lose their 

 identity, they are never transfoi-med into other tissue, and no other cells are ever 

 transformed into reproductive cells. 



The Vecetatiox Hoise as ax Aid ix Re.search. Bv J. C. .\rtiil;k. 



[Abstract.] 



The general construction and purpose of a vegetation house were described, 

 and examples of work ])erformed during the season of 1894 in the one at Purdue 

 university were given in illustration of what may Ije acc<)n)]dished when such 

 facilities are available. A vegetation house is essentially a structure to protect 

 growing plants from wind, rain, extremes of cold, atid other accidents to which 

 they are subject in the o]>en field. The plants arc grown in suitable pots or beds 

 mounted upon trucks, which run on wooden or iron tracks. The plants are only 

 run into the vegetation house when reipiiring protection, and at other times are 

 left in the open. Although the house is a glass structuri'. it has no heating 

 arrangements, and is chiefly nstnl during the summer season. 



Interesting results obtained by feeding oats and purslane with variable 

 amounts' of potash, were explained, and by growing potatoes with a greater or less 

 suj)})ly of water, and some other experiments. Photographs accompanied the 

 paper. Some possibilities in the study of the physiology of plants were outlined. 



Ma.ss and Moeecular Motion. Ey M. N. Ei rod. 



