The influence of Baer's scientific interest is recog- 

 nized first in the work Grube performed in Dorpat and 

 published in 1844 (see Chapter 25), and also in the inves- 

 tigations of Majewski and Tschernow, whose dissertations 

 were also defended at Dorpat University, in 1858. Both 

 these dissertations illustrated the embryo-physiological 

 problem of the chemical composition of the foetal fluids 

 in mammals. Majewski34 (121) investigated the composition 

 of the amniotic and allantoic fluids in twenty-eight embryos 

 of sheep (four to thirteen weeks old) and in sixteen embryos 

 of cattle (twelve to twenty-six weeks old), adding to this 

 data concerning some embryos of swine and man. In this work 

 he determined the weight, the length of the embryos studied, 

 the quantity of amniotic and allantoic fluids, their specific 

 gravity and reaction, and also the amount of solid constit- 

 uents, either organic or inorganic, namely albumin, sugar, 

 urea, phosphoric and sulphuric acids. In the tables of this 

 dissertation, numbers are given for separate observations and 

 average numbers for different periods of development. 

 Majewski established that, according to the extent of forma- 

 tion of the embryo, the amount of the solid constituents in 

 amniotic fluid increases. In particular, in all stages of 

 intra-uterine life in all investigated animals and in man, 

 the albumin and sugar are present in the amniotic fluid; the 

 quantity of albumin shortly before birth somewhat decreases, 

 and the quantity of sugar in the process of development of 

 the embryo gradually increases, reaching the maximum before 

 birth. The quantity of fluid in the allantois, and also 

 the content of solid matter in it, increases with the develop- 

 ment of the embryo. The allantoic fluid always remains 

 transparent and similar to the saturated urine, while the 

 quantity of urea in it gradually increases; in it there are 

 also albumin and sugar. On the basis of his investigations, 

 Majewski reached the conclusion that the amniotic fluid does 

 not serve to feed the embryo, but protects it from external 

 harmful influences and that the feeding of the foetus takes 

 place only through the placenta. 



34. Adolphus Majewski, polonus, DE SUBSTANTIARUM, QUAE 

 LIQUORIBUS AMNII ET ALLANTOIDIS INSUNT, DIVERSIS 

 VITAE EMBRYONALIS PERIODIS (Dorpat, 1858), 44 pp. 



484 



