12 MARGARET C. FERGUSON 



of development in the gametophytes of the Abietinece. has been 

 published. The details of these investigations are familiar to all 

 students of the subject. These papers will, therefore, be men- 

 tioned at this point by title only ; they will be referred to again 

 in the discussions which follow. Chamberlain (1899), Oogene- 

 sis in Pinus Laricio ; Wuicizki (1899), Ueber die Befruchtung 

 bei den Coniferen ; Arnoldi (1900), Beitrage zur Morphologic 

 der Gymnospermen, IV; Juel (1900), Beitrage zur Kenntniss 

 der Tetradentheilung ; Murrill (1900), The Development of 

 the Archegonium and Fertilization in the Hemlock Spruce 

 (Tsuga canadensis Carr.); Coulter and Chamberlain (1901), 

 Morphology of the Spermatophytes ; Ishikawa (1901), Reduc- 

 tion Division in Larix ; and the papers published by the writer 

 in 1901. l 



METHODS. 



Collecting. On November 15, 1897, and each week there- 

 after until December 25, cones of Pinus Strobus, P. rigida, P. 

 austriaca, P. montana var. uncinata, and the staminate strobili 

 of P. austriaca were collected. Material was brought in occas- 

 sionally during the remainder of the winter. Pistillate cones 

 of the species named, and also of P. resinosa, were collected 

 once each week beginning with April i ; collections were made 

 twice each week throughout the month of May, and three times 

 a week during June. From June 10-30, a period which was 

 sure to cover fertilization, cones of Pinus Strobus were collected 

 every day at about nine o'clock in the morning, and frequently 

 again at four o'clock in the afternoon. Male cones were gath- 

 ered, from those species in which they had appeared, at irregu- 

 lar intervals during the early spring. From the first of May 

 until the time of pollination, which varies by a number of days 

 in the different species, staminate strobili were collected each 

 day. During May and June the young female cones were 

 gathered as well as the more mature ones of the previous year's 

 growth. After July i, the older cones were no longer collected, 

 but the young cones of Pinus Slrobus, P. rigida, and P. austri- 

 aca were collected once each week until November 15. Cones 



1 See " Note " at close of Appendix. 



