billings: embryo nutrition in labiate. 77 



it continues it, in a way, out into the integument. It recalls 

 some of the haustorial outgrowths in the suspensor cells in 

 certain Orchidacese- and Rubiacese."' In Salvia lanceolata two 

 endosperm nuclei take part in haustorium formation; more 

 than two in Salvia azurea (fig. 18). In both species one end of 

 the haustorium completes the basal or proximal portion of the 

 suspensor. In Salvia lanceolata more of the suspensor is sur- 

 rounded than in Salvia azurea. In the former the suspensor 

 becomes bent while in the latter it remains straight. 



The haustorium grows outward through the integument, 

 taking a direction nearly at right angles to that taken by the 

 other haustoria. The purpose of the coenocytic haustorium 

 is to dissolve the integument cells surrounding it, but it is 

 unique in communicating the products of its activity to the 

 suspensor. Attention has already been called to the striking- 

 differences between the Salvia suspensors and those of the 

 other Labiatse examined. As the former take part in embryo 

 nutrition their cells present an appearance betokening activity. 

 Instead of losing their protoplasmic contents or undergoing 

 dissolution, as in instances where excessive elongation takes 

 place, the suspensor cells of Salvia are healthy appearing, re- 

 sembling the endosperm cells in this respect not a little. 



The coenocytic haustorium does not attain the size of the one 

 composed of tissue (fig. 19). As in similar haustoria previ- 

 ously described, the nuclei are larger than those of the endo- 

 sperm tissue. 



A canal, bent at nearly right angles, is formed between the 

 endosperm and the vascular bundle. There appears to be no 

 nucleus in it, but granular material resembling cytoplasm is 

 found along the side walls and at the end. As the main body 

 of endosperm pushes outward at the expense of the integument 

 cells, the canal does not suflFer for a time (fig. 20). Instead, 

 the endosperm becomes laid down around its proximal end. 

 This gives the appearance of the canal piercing the tissue. The 

 canal forms a direct communication with the vascular bundle, 

 serving probably as a conduction to the endosperm. 



Monarda flstulosa. 



This species is patterned after Lamium rather than after 

 Salvia. There is a large coenocytic micropylar haustorium 

 which does not diflfer materially from that of Lamium. A few 

 nuclei are present, though of a relatively smaller size. The 



