80 A NEW ZEALAND NATURALIST'S CALENDAR. 



seeds to some distance from them, I omitted to notice a 

 very common one, and one which is very familiar to many 

 horticulturists, though very few know it by name. The 

 plant I mean is a small bitter-cress (Cardamine hirsuta), 

 which is a most troublesome weed, not only in permanent 

 garden beds, but also in flower pots. Tt is such a typical 

 weed, such an excellently good example of what a weed 

 really is, that a short notice of it may not be out of place 

 here. 



We often use the word "weed" in its application to 

 human beings, to designate a poor miserable creature, of 

 feeble physical, mental, and moral development. In one 

 sense the term is right. Such a being is a survival, not of 

 the fittest, but of the unfit ; and such a survival is rendered 

 possible only by the artificial conditions under which most 

 human beings live. Similarly we speak of weeds among 

 horses, but we may be quite sure that there are no weeds 

 among wild horses. Weeds cannot exist in a state of 

 nature ; they are only an outcome of human activity, 

 paradoxical as such a statement may seem. 



So keen and fierce is the competition among all living 

 organisms that any individual not thoroughly equipped 

 for the struggle, or which from any caxise is unduly handi- 

 capped in the race for life, tends to be rigidly suppressed. 

 But man, with his sentient faculties, dislocates the natural 

 conditions to a greater or less extent, bringing into the 

 problems new factors, whose exact influence it appears 

 impossible to estimate. 



Thus, in the question before us now, the very process of 

 clearing the ground of its vegetation, of breaking the 

 surface of the soil and keeping it stirred, has furnished 

 during the ages a new factor in plant growth. There 

 has been evolved a race of plants, belonging to many 

 and different families, which have acquired the power of 

 growing under the new artificial conditions, and which 

 consequently we know as weeds of cultivation. However- 

 diverse their characters may be they agree in one point, 

 namely, that they are able to take advantage quickly of 

 these conditions and to thrive under them. Thus these 



