130 FROMME: SEXUAL FUSIONS IN FLAX RUST 
Explanation of plates 8 and 9 
PLATE 8 
Fic. 1. A branching, septate spermatiophore bearing spermatia on the finger- 
like elongations of the cells. x I,500 
Fic, 2. Another branched ipticuatinipbcve. The two upper cells have not as 
yet produced spermatia. The penultimate cell shows the beginning of the fingerlike 
outgrowth. X 1,500. 
A septate, unbranched spermatiophore.  X 1,500. 
Fic. 3a. A spermatium. X 2,250 
Fic. 4. A two-celled spermatiophore bearing spermatia. X 1,500 
5. A portion of a young aecidium showing a single layer of baci cells, 
the Serngstags with two layers of short sterile cells above and vegetative mycelium 
. The upper seen cells show conformity to the outline of the ov verlying 
nce An early ge of fusion is shown between the second pair of gametes 
from the Peay X 1,00 
IG. A young pair of gametes more highly magnified. Two short, crushed; 
sterile is are present above each gamete. X 1,500 
Cell fusion between two equal and parallel gametes. The upper 
portions of the intervening cell walls have been absorbed. +500. 
Fic. 8. An early stage in the fusion of two gametes. The absorption is at the 
center of the two cells, as the tips are not in contact. X 1,000. 
Fic. 9. One of the gametes lies somewhat below the other. 
Fic. 10. Fusion between two gametes, both of which still have two sterile 
cells intact. XX 1,000 
Fic. 11. A group of seven “fusion cells.” A triple cell fusion lies in the center 
of the group Win three double cell fusions on either side. One or more aecidiospores 
have been produced from most of the “fusion a ss 50 
FIG; 23.0 (8 fing of five ‘‘fusion cells,’’ 
IG. I of younger ‘‘fusion cells.’’ ae gametes on the left have just 
Conipleted the hese while those on the right have cut off the primary aecidiospore 
mother cell.  X 1,000. 
Fic, 14. A mature aecidiospore and a chain of intercalary and spore mother 
cells wiles have been cut off from the “basal cell” below. x 750. 
15 ne of the gametes functions as the “basal cell.” The cell 
the right has euies after the fusion and has cut off the primary paver 
mother cell.  X 1,000 
Fic. 16. An early stage of a triple cell fusion. X 1,00 
Fic. 17. A completed fusion between the tips of eee. pitts, X 1,000. 
PLATE 9 
8. Another type of triple cell fusion. Two aba cells in the same 
ents have fused with a single cell on the left. 1,00 
Fic. 19. A trinucleated spore mother cell borne on a trinucleated ‘basal cell,” 
which hes been formed by a triple cell fusion. he 1,000, 
Fic. 20. A trinucleated “ basal cell” whi i 1 tk 1 aecidiosr 
mother cell. The primary aecidiospore mother cell hee divided to form an aecidio- 
spore and intercalary cell. ,00 
Fic. 21. A mature trinucléated aecidiospore. X 1,000. 
Fic. 22. A mature aecidiospore containing six nuclei. X 1 1500. 
