It may be within the recollection of many of our readers, that although it was well-known that the Tom Thumb Arbor vitse was raised from the common arbor vitse, and that it is common for this and many allied plants to carry on their " free-leaved" or primitive condition for many years, or even for life, yet M. Carriere of Paris insisted that it must be something else, and re. named it "Retinospora Ellwangerania." According to the Gardener's Chronicle he has at length discovered that " Retinospora Ellwauger-iana is a form of Thuja." He seems to have started to doubt on "Retinospora ericoides," which he now asserts "is a Biota," - that is, a form of Chinese arbor vitse. It would not hurt M. Carriere to read American publications.