THE HIGHER CRYPTOGAMIA. 433 



pro-embryo for the embryo. Hartig* was the first to 

 observe that the upper part of the suspensor is a single 

 row of cells. He had not a clear idea of the relation of the 

 suspensor to the pro-embryo. Mirbel and Spachf dis- 

 covered the breaking up of the pro-embryos into single 

 rows of cells in Pin as, Thuja, and Taxus. Gottsche'sf 

 excellent work contains the most careful critique of the then 

 known facts, and the first accurate description of the struc- 

 ture of the corpuscula of Pinus ; it also gives a renewed 

 and complete proof of the advance of the pollen-tube to the 

 corpuscula, as well as proof of the fact that the rudiment 

 of the pro-embryo is visible in the lower end of the cor- 

 pusculum, whilst the sister-cells of the germinal vesicle are 

 still present. 



The greater part of the above investigations were under- 

 taken in the years 1848 and 1849.§ I have already 

 mentioned their agreement with Pineau's views, and their 

 divergence from those of Geleznow and Schacht. 



* ' Naturgeschichte der Forstcultur pflanzen,' Erklarung zur Tafel, XXV. 



f ' Ann. d. Sc. nat.,' ii Ser. vol. xx, p. 257. 



% <Bot. Zeit.,' 1845, 377. _ 



§ Bead at the August sitting of the Leipzig Natural History Society. 



2S 



