1909] THOMSON— POLLEN OF MICROCACHRYS 27 



in intimate association with the pollen, they frequently branch, and 



form 



o 



This pollen is no different 



from the less abundant found in uninfected sporangia. 



The pollen of Microcachrys (fig. 8) is small as compared with 

 that of Saxegothaea (fig. p), Podocarpus (fig. 10), or Pinus (fig. 11), 

 all these figures being the same magnification for the purpose of 

 comparison. The grains vary considerably in size, a feature which 

 my material of Saxegothaea also shows. They are winged, though 

 in some instances I have thought that no wings were present, but 

 more material was needed to determine this point than was at my 



disposal. 



ordinary 



the exine from the intine. In longitudinal section the grains usually 

 show two rather poorly developed wings (see various grains in fig. 6), 

 and in following the series these two are often all that one can be 

 certain of. In gross material, however, three wings are readily 

 apparent (fig. 8). 2 In transverse sections, also, which pass through 

 the ventral part of the grain, the three-winged condition is clearly 



(fig 



fig. 6). In some cases one of the wings is very 



field). The lowest grain in 



fig- 6 shows the presence of four wings (the cei 

 Some four- winged grains have one pair of wings much smaller than 

 the other. Exceptionally, five and six-winged grains are found. A 

 student, Mr. W. P. Thompson, kindly made a careful determination 



gross 



the grains in fluid under the cover glass. He 



very 



wing; nine were four- winged ; two had five, and three had six wings. 



mature 



ave been fully developed. Fig. 7 shows the greatest expansion of 

 the wings that I have observed. They usually do not extend laterally 

 beyond the body of the grain (fig. 8, also some grains in fig. 6). 

 ey project, however, beyond the body of the grain ventrally, 

 though not to such a degree in either direction as do those of Podo- 

 carpus (fig. I0 ) or Pinus (fig. 11). A small amount of material from 



e apex of one of the cones showed another feature. When the 



of thl StUdled the S rain s in section first, and this led me to misinterpret the number 



wmg S , as stated in Box. Gazette 46:465, 466. 1908. 



