variety in correlation with the loss of the blue tint.  According to Sprengel, this plant is strongly proterandrous (11/14.  ’Das Entdeckte’ etc. page 278.); it would therefore be more or less sterile unless bees carried pollen from the younger to the older flowers.  Consequently the white variety, the flowers of which were always bitten instead of being properly entered by the bees, would fail to yield the full number of seeds and would be a comparatively rare plant, as Dr. Ogle informs me was the case.

Bees show much skill in their manner of working, for they always make their holes from the outside close to the spot where the nectar lies hidden within the corolla.  All the flowers in a large bed of Stachys coccinea had either one or two slits made on the upper side of the corolla near the base.  The flowers of a Mirabilis and of Salvia coccinea were perforated in the same manner; whilst those of Salvia grahami, in which the calyx is much elongated, had both the calyx and the corolla invariably perforated.  The flowers of Pentstemon argutus are broader than those of the plants just named, and two holes alongside each other had here always been made just above the calyx.  In these several cases the perforations were on the upper side, but in Antirrhinum majus one or two holes had been made on the lower side, close to the little protuberance which represents the nectary, and therefore directly in front of and close to the spot where the nectar is secreted.

But the most remarkable case of skill and judgment known to me, is that of the perforation of the flowers of Lathyrus sylvestris, as described by my son Francis. (11/15.  ‘Nature’ January 8, 1874 page 189.) The nectar in this plant is enclosed within a tube, formed by the united stamens, which surround the pistil so closely that a bee is forced to insert its proboscis outside the tube; but two natural rounded passages or orifices are left in the tube near the base, in order that the nectar may be reached by the bees.  Now my son found in sixteen out of twenty-four flowers on this plant, and in eleven out of sixteen of those on the cultivated everlasting pea, which is either a variety of the same species or a closely allied one, that the left passage was larger than the right one.  And here comes the remarkable point,—­the humble-bees bite holes through the standard-petal, and they always operated on the left side over the passage, which is generally the larger of the two.  My son remarks:  “It is difficult to say how the bees could have acquired this habit.  Whether they discovered the inequality in the size of the nectar-holes in sucking the flowers in the proper way, and then utilised this knowledge in determining where to gnaw the hole; or whether they found out the best situation by biting through the standard at various points, and afterwards remembered its situation in visiting other flowers.  But in either case they show a remarkable power of making use of what they have learnt by experience.”  It seems probable that bees owe their skill in biting holes through flowers of all kinds to their having long practised the instinct of moulding cells and pots of wax, or of enlarging their old cocoons with tubes of wax; for they are thus compelled to work on the inside and outside of the same object.