The Life History of Polythrincium Trifolii Kunze. 225 



kept at a cool temperature, the soil remaining damp. When one 

 of the leaves was examined, a tendril was seen to be exuding 

 from the ostiole of one of the stromata. The exudation was 

 transferred to a shde for microscopic examination, and an 

 ascus containing eight large spores was found embedded in the 

 mucilage. The spores measured 19 x 10 /z, and contained two 

 large guttulae. The spores were left in a damp condition, but 

 even after 4S-72 hours, there was no sign of germination. The 

 leaflet from which the exudation was taken was sectioned in 

 order to observe the method of growth of the asci and peri- 

 thecia. Perithecial ca\ities containing ascogenous tissue were 

 found in abundance, but there was no sign of a mature peri- 

 thecium. The leaves were again placed between iv}- leaves, and 

 put out of doors for examination later in the season. On Novem- 

 ber 22nd, 192 1, three other pots were prepared in the same way, 

 each containing six clover leaves. On December 6th, one of 

 these pots was brought indoors to dry slowly (as dr\-ing might 

 perhaps stimulate the formation of ascospores), and examined 

 after four to five weeks, but there was no sign of mature asci. 

 On January 29th, 1922, another pot was examined, but again 

 there were no mature asci. The leaves were replaced and the 

 pots kept moist in a cool greenhouse for several weeks. On 

 January 31st the pot which had pre\'iously showTi ascospores 

 was again inspected but there was no trace of clover leaves or 

 stromata, this doubtless being due to the partialitv of soil 

 animals for the fungus. It was now thought ad\-isable to place 

 the clover leaves of the pots pre\'iously examined between co\-er 

 slips or glass shdes before bur\"ing them, so that on the dis- 

 integration of the leaf the stromata could be found easilv. On 

 February 23rd, a portion of a stroma from one of the clover 

 leaves which had been placed between cover shps was examined 

 and asci were found containing spores which were not quite 

 mature. The asci grew in clusters from the base of the peri- 

 thecium (fig. 6) . The spores in the asci were more or less biseriate, 

 and uniseptate and granular (being not fully matiu-e) and 

 measured from 24-26 x j^ /n (fig. 6) ; no paraphyses could be 

 seen. Some of the material from which the stroma had been 

 taken was fixed in Bouin's fluid, embedded in wax, microtomed 

 and stained in iron-alum haematoxylin. The rest of the material 

 was replaced between cover shps and buried between ivy leaves 

 in soil, when further development took place and finally mature 

 ascospores were obtained. 



The stromata bearing ascogenous tissue are very similar to 

 the pvcnidial stromata, in fact p)erithecia occur in the same 

 stromata as pycnidia. No trace of any archicarp has been found. 

 the first indication of primordial perithecial tissue being a few 



