The plant which performs this strange feat is the Tillandsia usneoides, indigenous to tropical America, and generally known as 'Spanish Moss'. Its peculiarity is that it grows and flourishes without taking from its support any material whatsoever for the building up of its substance. Its natural habitat is the dry bark of virgin forest trees. Since civilization invaded its home it has acquired the habit of growing even on telegraph wires, which has given it the popular name of 'telegraph tresses'. Chemical analysis of this plant shows the presence of an average of 17 per cent iron, 36 per cent silicic acid and 1·65 per cent phosphoric acid. This applies to samples taken from districts where the rainwater - the only source from which the plant could extract these substances in physical form - contains at most 1·65 per cent iron, 0·01 per cent silicic acid and no phosphoric acid at all.
The Tillandsia phenomenon is to a certain extent reminiscent of another well-known plant activity. This is the process of assimilation of carbon from the carbon dioxide of the air. If we leave aside the change in the chemical combination which the carbon undergoes, there remains the picture of the plant drawing this matter to itself from its environment and at the same time subjecting it to a spatial condensation. A similar but even more far-reaching process is exhibited by the Tillandsia as regards the three substances referred to above. From the conditions given, it follows that the plant cannot possibly get these substances elsewhere than out of the surrounding atmosphere, and that in drawing upon them it submits them to a high degree of condensation. A special role, however, is played by the phosphorus, which shows that the assimilative power of the plant is sufficient to transform phosphorus from a physically not traceable state into one of spatially bounded materiality. Following Goethe in his coining of the concept of 'spiritual anastomosis' for the pollinating process of plants, we can here speak of 'spiritual assimilation'.
In this respect Tillandsia provides an instance 'worth a thousand, bearing all within itself. For what nature here unmistakably demonstrates serves as an eye-opener to a universal fact of the plant kingdom and of nature in general. The problem of the so-called trace-elements may serve as an illustration of this.
Modern agricultural chemistry has found of a number of chemical elements that their presence in the soil in scarcely traceable amounts is necessary in order to enable the plant to unfold healthily its latent characteristics. All sorts of deficiencies in cultivated plants have led to a recognition that the soil is impoverished of certain elements by intensive modern cultivation, and that it is to the lack of these elements that the deficiencies are due. Much work has meanwhile been done in classifying the various deficiencies and in devising ways of giving the soil chemical substitutes for what is lacking.
A large part of the work here involved could be saved were it only to be acknowledged that the soil owes the natural occurrence of the proper elements to a process which the plants themselves bring about in the soil, if men refrain from hindering them by cleverly thought-out methods of cultivation which fail to reckon with the nature of a living organism.
Let us be clear what it is that occurs when a plant exhibits any of the observed abnormalities. Expressed in a Goethean manner, these are the consequence of an insufficient direction of the organic processes in the plant body by the spiritual plant-type underlying it. That which Ruskin called the 'spirit' of the plant, and to which he drew attention in his aphorism 'Stand by Form against Force' (by 'form' all the peculiar qualities of the plant are to be understood), is unable to express itself in full measure. Now we know that, in order to unfold its activities on the physical plane, spirit requires 'young' matter - that is, matter which is either in, or has just emerged from, a purely dynamic state. Normally a definite spiritual type co-ordinates the dynamic functions present in the superphysical sphere of nature in the manner required to give the plant-organism its appropriate form. As, through the action of the type, these functions are brought down from the sphere of levity into that of gravity, they condense to the corresponding material elements and thus reach the soil in material form via the physical organism of the plant.
The pattern as usually seen is now reversed; the presence of the various elements in the soil no longer appears as the origin of one or another function in the building up of the plant-body, but quite the reverse. The functions appear now as the cause, and the soil-elements as the effect. We may thus recognize the value of the latter as symptoms from which we can read the existence of a healthy connexion between the plant and the corresponding form-creating functions working on it from its surroundings.
With this reversal of the relationship between cause and effect it is not, however, intended to represent the commonly accepted order of things as entirely incorrect. In the realm of life, cause and effect are not so onesidedly fixed as in the realm of mechanical forces. We may therefore admit that a reverse effect of the soil-elements upon the plant does take place. This is plainly demonstrable in the case of phosphorus which, however, by reason of its appearance in the soil in proportions hardly to be called a mere 'trace', represents a borderline case. What may apply within limits to phosphorus is wholly valid for the trace-elements - namely, that they are playing their essential role while they are themselves about to assume ponderable form.
It thus becomes clear how mistaken it is to attempt to cure deficiencies in plants by adding to the soil chemical substitutes for the trace-elements. In the condition in which this material is offered to the plant, it is truly 'old' material. In order to be able to use it functionally, the plant has first to convert it into the 'young' condition. This indeed happens whilst the material is rising in the plant combined with the juices drawn by the plant from the soil under the influence of levity-force. Only when this has occurred are the chemical elements able to serve the plant functionally. Thus, by trying to give help to the plant in this way, we injure it at the same time. For by forcing it to perform the operation described, its general life-forces are diminished. A seeming success brought about in this manner, therefore, will not last long.6
There is, nevertheless, a way of helping the plant by adding to the soil certain material substances, provided these are first brought into a purely dynamic condition. That this can be done is a fact long since known, even if not recognized in its true significance. So far then, as serves the purpose of this book, we shall deal with it here.