Again, Mr. Darwin's MS. quotes from Sir B. Brodie's 'Psychological Inquiries' (1854, p. 88) the following case, which is analogous to the above, except that the supports required had to be made in a vertical instead of in a horizontal direction:-- On one occasion, when a large portion of the honeycomb had been broken off, they pursued another course. The fragment had somehow become fixed in the middle of the hive, and the bees immediately began to erect a new structure of comb on the floor, so placed as to form a pillar supporting the fragment, and preventing its further descent. They then filled up the space above, joining the comb which had become detached to that from which it had been separated, and they concluded their labours by removing the newly constructed comb below, thus proving that they had intended it to answer a merely temporary purpose. Similarly, Dr. Dzierzon, an experienced keeper of bees, and the observer who first discovered the fact of their parthenogenesis, makes the general remark,-- The cleverness of the bees in repairing perfectly injuries to their cells and combs, in supporting on pillars pieces of their building accidentally knocked down by a hasty push, in fastening them with rivets, and bringing everything again into proper unity, making hanging bridges, chains, and ladders, compels our astonishment. Lastly, as still further corroboration of such facts, I shall quote the following from Jesse's 'Gleanings:'[65]-- Bees show great ingenuity in obviating the inconvenience they experience from the slipperiness of glass, and certainly beyond what we can conceive that mere instinct would enable them to do. I am in the habit of putting small glass globes on the top of my straw hives, for the purpose of having them filled with honey; and I have invariably found that before the bees commence the construction of combs, they place a great number of spots of wax at regular distances from each other, which serve as so many footstools on the slippery glass, each bee resting on one of these with its middle pair of legs, while the fore claws were hooked with the hind ones of the bee next above him; thus forming a ladder, by means of which the workers were enabled to reach the top, and begin to make their combs there.