THE MICROSPORANGIUM 43 



as ushering in the gametophyte was first urged by Stras- 

 burger, 12 whose paper closes as follows: 



u The reduction in number of the chromosomes takes place, 

 among the higher plants, in the mother-cells of the spores, and 

 it is consequently these which must be regarded as the first 

 term of the new generation. They assert this their true sig- 

 nificance in that they usually isolate themselves from cohesion 

 with other cells and become independent, although this inde- 

 pendence is only of practical utility in the case of the products 

 of their division that is, of the spores. Hence the center of 

 gravity of the developmental processes which take place in both 

 micro- and macrosporangia of Cryptogams and Phanerogams 

 does not lie in those cells, cell-rows, or cell-aggregates which 

 give rise to the sporogenous tissue and have been designated 

 ' archesporium ' by Goebel. The archesporium still belongs 

 to the sexually developed asexual generation; it is only the 

 spore mother-cells which initiate the new sexual generation; 

 consequently the presence or absence of a well-defined arche- 

 sporium is not a matter to which importance should be 

 attached." 



LITERATURE CITED 



1. PURKIXJE, J. E. De cellulis antherarum fibrosis nee nori de gra- 



norum pollinarium formis commentatio phytotomica. Vrati- 

 slaviae. 1830. 



2. NAGELI, C. Zur Entwicklungsgeschichte des Pollens. Ziirich. 



1842. 



3. HOFMEISTER, W. Xeuere Beobachtungen iiber Embryobildung 



der Phanerogamen. Jahrb. Wiss. Bot. 1: 82-188. pis. 7-10. 

 1858. 



4. ROSAXOFF, S. Zur Kenntniss des Baues und der Entwicklungs- 



geschichte des Pollens der Mimoseae. Jahrb. Wiss. Bot, 4 : 441- 

 450. pis. 31-32. 1865. 



5. ROHRBACH, P. Die Samenknospe der Typhaceen. Bot. Zeit. 27 : 



479-480. 1869. 



6. KAUFFMAXN, N. Ueber die mannlichen Bliithe von Casuarina 



quadrh-ah-is. Bull. Soc. Nat. Moscou 41 : 374-382. 1869. 



7. MAGNUS, P. Zur Morphologic der Gattung Naias L. Bot. Zeit. 



27 : 769-773. 1869. Also Beitrage zur Kenntniss der Gattung 

 Xaias~L. Berlin. 1870. 



8. WARMING. E. Untersuchungen liber pollenbildende Phyllome 



und Kaulome. Hanstein's Bot. Abhandl. 2: 1-90. pis. 1-6. 

 1873. 



