SUMMARY AND CONCLUSIONS 65 
(a) The form and cytological structure .of these cells, and the 
changes of their food content. 
(4) Their tendency in some plants to multiply and form a 
special tissue, of the nature of conductive or nutritive tissue. 
c) The behavior of the surrounding tissues notably the arche- 
sporial cells, which are absorbed. 
We may not overlook the case of Cructanella, for which evi- 
dence is lacking that the antipodals play any but a very brief, 
passive role. 
7. The embryo in the GaZeae develops rapidly, especially in 
its early stage, and possesses a remarkable feature in the presence 
of a highly developed embryonic organ, the suspensor, the 
cells of which elongate laterally, and penetrate the surrounding 
endosperm in an intercellular manner without causing any disinte- 
gration of the endosperm. These outgrowths are termed haustoria. 
Analogous organs are known in a number of forms, and probably 
occur in many more in one form or another. The function of the 
suspensor in these forms is therefore not alone to bring the embryo 
into favorable position with relation to the food supply in a me- 
chanical sense, but to act as a temporary embryonic root. This 
function is secondary, the former being regarded as primary, as for 
example in the case of Selaginella * in which it appears to have no 
further significance. 
A strikingly analogous condition appears in certain species of 
Tropaeolum, according to Dickson, in which the embryo pro- 
duces “ branches from the base of the suspensor ” which “ serve 
as organs of nutrition for the developing embryo— foetal roots, in 
fact" These organs penetrate into the pericarp. 
Similar organs have been described by Treub f in the Orchida- 
ceae and by Hofmeister,$ followed by Guignard || in the Legu- 
minosae. 
Pfeffer, W. Die Entwickelung des Keimes der Gattung Se/agınella. Hansteins, 
bot. er 1: No 
fOn the تسس‎ of Tropaeolum peregrinum (L.) and T. speciosum (Endl. 
rt 
and Paepp.). Trans. Roy. Soc. 17 : Part 2. 
t Notes sur l'embryogenie ye quelques Orchidees. Naturk. Verh. K. Akad, 19: 
1879. 
2 Die Entstehung des Embryo der Phanerogamen, 1849. 
l| Ann. sci. nat, VI. 12: 5. 1881. 
