. The Pharmaceutical era. wet places manifestthe production of a knee-like joint. The form of theroot-branches is that of an inverted \. They may exer-cise a mechanical influence to support the tree, but itmay be also to allow the roots to obtain more air. Itseems singular that the Bald Cypress does not produceknees in dry soil and always does so when the roots aresubmerged. It is further singular that full-grown treesthat have masses of knees surrounding them are lostwhen the soil in which they live has been drained. What-ever the function, be it to furnish air to the plant or toserve as a me
. The Pharmaceutical era. wet places manifestthe production of a knee-like joint. The form of theroot-branches is that of an inverted \. They may exer-cise a mechanical influence to support the tree, but itmay be also to allow the roots to obtain more air. Itseems singular that the Bald Cypress does not produceknees in dry soil and always does so when the roots aresubmerged. It is further singular that full-grown treesthat have masses of knees surrounding them are lostwhen the soil in which they live has been drained. What-ever the function, be it to furnish air to the plant or toserve as a mechanical support to the tree under theseconditions, this development only takes place under theselieculiar conditions, i. e., when the roots grow in wetplaces. (.j) Parasites and Saprophytes. —There are furtherplants which produce elements corresponding to roots,but they penetrate the tissues of other plants in orderto secure their nourishment. These rootlike elementsare called Haustoria. There are two classes of plants. January 13, 1898.] THE PHARMACEUTICAL ERA. 49 which possess Haustoi-ia, viz.: (1) Those that aro trueparasites or ijrecn parasites, iu that they take up oulythe crude materials which the roots of the host planthave absorbed; and, (2) Saprophytes, which do uot ac-cept crude materials from the host, but take the digestedor elaborated food materials As an example of a true x>arasite we have theMistletoe (coming from two Greek words meaning athief ou a tree) which live on oaks, elms, apples, etc. Among Saprophytes we mention the common Dodder(Cuscuta) which lives on a great many different plants,as species of Linum, Polygonum, Compositiie, Legum-inosete, etc. Each species of Dodder has its particularhost on which it lives. They are among the most trou-blesome of parasitic weeds to the gardener and farmerin the Old World. Some of the species have become sodestructive in French agriculture and horticulture, thatthe Prefect of one of the large provinces, C
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Keywords: ., bookcentury1800, booksubjectdrugs, booksubjectpharmacy, bookyear1
