398 Groom. — On the leaves of L at hr aea Squamaria. 
Literature. 
1. Scherfff.l : Die DrUsen in den Hohlen der Rhizomschuppen von Lathraea 
Squamaria. (Mitth. a. d. Bot. Inst. z. Graz, 1888, Heft 2, pp. 187-212.) 
2. Gilburt : On the Structure and Function of the Scale-leaves of Lathraea 
Squamaria. (Journ. Royal Microsc. Soc., Oct. 1880, pp. 737-741.) 
3. Hovelacque : Recherches sur l’appareil vegetatif des Bignoniacees, Rhinan- 
thacees, Orobanchacees et Utriculariacees : Paris, 1888. 
4. Cohn : (A paper not seen by me, in Jahresber. d. Schles. Ges. : Breslau, 1877, 
pp. 1 1 3-1 14.) 
5. Krause: Beitrage zur Anatomie der Vegetationsorgane von Lathraea 
Squamaria. (Inaug. Diss. Breslau, 1879.) 
6. Heinricher : Appendix to Scherffel’s paper quoted above. 
7. Bowman : On the parasitical connexion of Lathraea Squamaria and tire 
peculiar structure of its subterranean leaves. (Trans. Linn. Soc., Vol. xvi, 
1833. P- 399-) 
8. Groom, P. : Contributions to the knowledge of Monocotyledonous Saprophytes. 
(Journ. Linn. Soc., XXXI, 1895, PP* I 49 _2I 5*) 
Postscript. 
This investigation was concluded in June, 1896, and the 
present paper was written, exactly as it now stands, in the 
autumn of the same year, but its publication has been un- 
avoidably delayed. In the meanwhile, G. Haberlandt 1 and 
Goebel 2 have almost simultaneously published papers on 
Lathraea. Both these investigators agree with me that the 
subterranean scales of Lathraea excrete water into their 
chambers, and that the specific function of some of the glands 
lining these cavities is to rid the plant of an excess of water. 
Haberlandt concludes that the capitate hairs alone are 
responsible for the excretion of water : whereas Goebel sug- 
gests that this function is performed especially by the 
dome-shaped glands ( Schilddriisen ). My paper, I think, 
contains sufficient proof that it is the dome-shaped glands 
which are the definite water-excreting organs — the hyda- 
thodes. 
1 G. Haberlandt - , Zur Kenntniss der Hydathoden : Jahrb. f. wissensch. Bot., 
xxx, Heft 4, 1897. 
2 Goebel, Ueber die biologische Bedeutung der Blatthohlen bei Tozzia und 
Lathraea: Flora, Bd. lxxxiii, Heft 3, 1897. 
