SCULPTURE OF THE TESTA OF GERMAN JUNCACEZ. 151 
glumis, and biglumis). In length they are the largest (being 1*4 line 
in J. castaneus) ; and even after deducting the appendage the body of 
the seed is much larger than that of the other species. The ecau- 
date seeds are mostly about } line long; on the average the seeds 
of J. Tenageja, spherocarpus, compressus, pygma@us, and capitatus are 
about + line smaller. e seeds of J. Balticus are considerably 
larger than the average size (being as large as 4 line), Æreticus (which 
is nearly as large as the foregoing), and J. sguarrosus (which is the 
same size as J. Balticus). In nearly all caudate seeds the ribs of the 
testa are very prominent, and the meshes formed by them are nearly 
always arranged lengthwise (J. Jacquini, acutus, stygius, castaneus, tri- 
glumis, trifidus, and monanthos); we find meshes of nearly equal 
length in J. maritimus and biglumis. Transversely-placed meshes do, of 
course, not occur where the ribs are very much developed ; and if in some 
parts of the seeds of J. ¢rifidus and monanthos elevated transverse, 
pretty equidistant, lines are often noticed within the longitudinally- 
placed meshes of the external membrane ; these transverse lines are on 
the inner brown membrane, and glimpses of it can only be caught in 
places where the outer membrane is dried up. A very regular rectan- 
gular reticulation, with delicate, transversely-striated meshes, occurs in 
the species with articulated leaves. J. pygmaeus, sylvaticus, lampo- 
carpus, atratus, alpinus, and supinus agree in this respect; whilst 
J. obtusiflorus differs from them by its delicately-dotted meshes. Re- 
gular reticulation, with smooth meshes, occurs in J. capitatus, squar- 
rosus, and Balticus. Closely packed transverse ‘meshes (“semina 
lineolata”) of Engelmann—a term which becomes intelligible when it 
is borne in mind that indeed the elevated transverse lines are the most 
prominent of all— are noticed in J. conglomeratus, effusus, glaucus (curi- 
ously enough only on the sides of the seeds, whilst the back has a 
regular reticulate system of ribs), paniculatus, tenuis, Tenageja, sphero- 
carpus, and bufonius. The ecaudate seeds are generally oblique, ob- 
ovate or pear-shaped, seldom lancet-ovate (J. capitatus, Tenageja, 
atratus, and alpinus), truly elongate-lancet (J. sylvaticus) or doliiform 
(J. bufonius). The raphe is mostly shorter than the outer strongly- 
curved side of the seed, to which the obliquity of the seed is due. The 
chalaza is in appearance like a projecting point, easily distinguished 
from the other parts of the seed by its much darker colour. 
In conclusion, let us turn to the seeds of our species of Luzula. 
