16 DR. J.D. HOOKER ON THE STRUCTURE AND 
tuose in some species of Balanophora: in all the Helosidee they burst introrsely, and 
also by their apices, which decay away, and thus allow the pollen to escape. : 4 
The tissues of the anthers present little peculiarity ; that of the connective is simply 
cellular, without any of the spiral vessels or beautiful modifications of banded or annulate 
cells, so conspicuous in the endothecium of many plants. It is frequently lined with a . 
pulpy mass of mucilaginous filaments of excessive tenuity, which appears to be the | 
remains of the tissue amongst which the pollen-cells were elaborated. - = 
The pollen of various species has been carefully described by Gæppert, Griffith, and — 
others, and presents nothing remarkable: it is generally spherical, often 3-lobed or 3- 
nucleate; in Mystropetalon it is polygonal. The surface of the extine is occasionally 
minutely granulated. Impregnation is probably mainly effected by insect agency, and at 
night; for during the day there is a singular want of insect life in the still, humid forests 
frequented by the species of Balanophora. I have, however, failed in many attempts to 
trace insect action; and a small Acarus feeding on the pollen of the monæcious B. invo- 
lucrata is the.only one I have found to be concerned in the operation, and that no doubt 
quite accidentally. The necessity of cross impregnation is manifest in the Helosidee, as 
indicated by Richard, and elsewhere explained in this Essay (under the genus). The fact 
of insects forming a nidus in the fleshy plants of this Order, has been used as an argument 
in favour of insect action assisting in impregnation; but the same might be applied to — 
any fleshy fungus or fruit. 
Ovaries.—These vary in number, from one in the Monostyli and Sarcophyte, to two in 
the Distyli ; and, according to Endlicher, to sometimes three in Helosis and Scybalium. 
When there are more than one, they are congenitally coherent, enclosed within the ad- 
herent perianth, and all the cavities but one are suppressed (being rarely present, according b 
to Endlicher and Schott, in some flowers of Helosis and Scybaliwm), whilst the styles — 
invariably remain, and are equal, and symmetrically disposed (right and left to the axis) 
at the summit of the perfectly symmetrical one-celled ovary. In those species which 
have a perianth, it may be traced surrounding the ovary, if examined before the latter 
begins to swell, and at all periods in some species; in most, however, the walls of the 
ovary become indurated, and blend insensibly with the adherent perianth, whose limb 
ee on à rud lea ae o the EHE in the Lophophyteæ it 
ture has been alread ax lai ed en ig Mats ee SASE ep Ade dte ric 
a y explain uud 'ongst the Monostyli the ovary is always one-celled; 
gsdorffia and Thonningia it is enclosed in a very evident perianth. In Bala- 
nophora there are not even rudimentary traces of a perianth. 
sit pre, ll, d Maw 
few oblong cells surrounding pei pulpy en en d Aes 
distinct stigma, and the termination of the style WR fr did. 
fiogu M a ee J'e scarcely differs from any other part of 
I have found a the ks t gi Sag ee = horis die Nig $i å 
- capitate, and rather more ek in th ina å er ho; De gr. 
globular cells. After ee Be så cras Eies par larger, oen 
| 'gnation, ese cells, when very highly magnified, 
