I was chatting the other night on the topic of growing zucchini with a friend who also shares some interest in detective fiction. During the discussion, when I realized that I was aware of two connections between the topics of detective fiction and zucchini, I couldn’t resist the opportunity to make a note. Since detective fiction relies upon surprise, and it seems a shame to spoil anyone’s surprise, I will say that if you read any further you will lose some potential surprise if you ever track down an obscure novel by the obscure author John Rhode called Vegetable Duck, which today will set you back US$150. Consider yourself warned.
Thanks to Wikipedia, I can state fairly authoritatively that the marrow (vegetable, as opposed to, say, bone marrow) is the mature fruit of “certain Cucurbita pepo cultivars”; the immature fruit is called courgette in the British Isles and various countries and zucchini in North America and elsewhere. The foodstuff that I know as zucchini is immature, I gather, and will form a harder skin and become very gourd-like if allowed to come to full maturity. The Internet seems remarkably silent on the topic of what happens when it becomes a gourd — does anyone do this? — but I imagine it would be very fibrous, and treated very much like a squash if you chose to eat it.
Hercule Poirot, of course, in the opening moments of Chapter Four of The Murder of Roger Ackroyd (1926) is said to be “interested in the growing of vegetable marrows”, and the reader with a long memory will remember that “vegetable marrows” are literally the final two words of this genre-transforming book. (I shall henceforth refer to these things as zucchini since that’s the word I’m accustomed to use.) Interestingly, they seem to have been first introduced to Europe from the Americas in the very late 19th century, developed into new forms in Italy, and then introduced back into North America in “the early 1920s”.
I think that’s interesting. It may well be that Poirot’s retirement was not, as I’d always thought, because he wanted to learn how to grow vegetables to prize-winning sizes. I’d rather seen him competing full-on for blue ribbons at countryside agricultural fairs, and attempting to bring order and method to the production of enormously oversized zucchini. But if zucchini were … perhaps not the latest thing in every circle, but on the horizon of people with educated palates in 1926, perhaps mentioned in newspapers or on the radio, Agatha Christie might have been saying something about Poirot’s degree of education. I’ll hesitantly suggest that she might have been trying to show him as the kind of middle-aged guy who retires and begins to market some sort of labour-intensive artisanal foodstuff, like fireweed honey or chevre, at very high prices. I can’t say I’m able to really advance this strongly, but it’s interesting to think about.
In fact, in Chapter Four of Roger Ackroyd, we meet Poirot because in a fit of rage he throws a large zucchini over the wall of his garden and nearly hits the narrator. (And it falls to the ground with a “repellent squelch”, which suggests it was the softer-skinned zucchini with which I’m familiar.) He’s been cultivating them for months and has suddenly become upset with … well, it’s not absolutely clear, but I think we are meant to know that they’re not large enough to suit him. Apparently Poirot and, by extension, Agatha Christie were not aware of a little trick with zucchini that I learned from another mystery writer, John Rhode, in his 1944 mystery Vegetable Duck.
Now Vegetable Duck, for the mystery enthusiast intent upon making zucchini connections with detective fiction, is a very useful book indeed. (I hasten to add that you are unlikely to ever read it, given its current state of availability: it went through a second edition in 1946, probably the “cheap”, and has never been republished. My copy was marked CDN$150; it’s now copyright-free in Canada, where I live, so perhaps I’ll scan it and donate it to archive.org.) I’m not going to go into too much detail about the book itself, but you already know where this is going; I will now spill the beans about the zucchini, as it were. This book contains a murder that’s committed by poisoning a zucchini.
There are two bits of this that need explaining, though, so you’ll understand the method. The first is that the “vegetable duck” of the title is apparently a wartime recipe. You take a large zucchini, stuff it with minced meat and herbs, and bake it whole. There’s a reference to “a baking tin, containing half an inch of solidified dripping”. I have no real idea why there’s dripping (liquefied fat); My instinct would be to bake this in water, perhaps wrapped in foil, but it’s not clear to me how much meat is in this recipe or why it would leak fat, or how. I cannot think of any way to sensibly make this recipe without slicing the zucchini lengthwise and hollowing it out a bit, but the book jacket suggests that the zucchini is somehow cored and then sliced into rings of zucchini with a central core of filling. And in chapter 6, the housemaid/cook says:
“… [S]he had cut a piece off one end, [of the zucchini] and scraped out the seeds.”
Then notes that she had taken the remainder of a joint of mutton off the bone…
“… and minced it. To this she had added a chopped-up onion, parsley, herbs, and a little dripping. With this mixture she had stuffed the interior of the marrow, which she had then put back in the larder.”
Now, can you imagine trying to scrape out the centre of a zucchini without slicing it in half? This would take me forever unless there’s a specialized tool that does the job, and I don’t know of it. No one mentions that this takes four hours of the maid’s time, though, so there’s something going on here beyond my limited culinary skills.
The second part is how the zucchini is poisoned and, as I warned you above, this is probably more than you want to know if you ever hope to read this book. I’ve included a photograph of zucchini in situ so you can follow along. Apparently you take a piece of yarn, soak it in liquid and thread it into a sturdy needle, and pierce the stem of a zucchini close to the main body of the plant so that the yarn passes through the stem. Then you put the ends of the yarn into containers of liquid. In some way the zucchini will absorb the liquid from the container via the yarn in its stem, and thereby grow larger than it would ordinarily.
If you’re a grower of vegetables for entering into agricultural contests, your containers are filled with water in order to increase the size of the zucchini so you’ll win the blue ribbon. And if you’re a character in a book, your liquid contains a solution of, say, gelseminine hydrochloride sufficient to kill your enemy to whom you’ve fed vegetable duck.
The osmotic administration via yarn would not be considered entirely sporting in British agricultural circles, I’m sure, which is perhaps why Hercule Poirot didn’t try it. Either that or, more probably, that Agatha Christie had been insulated from the dirtier secrets of the process required to produce prize-winning zucchini.
Now, I can testify from personal experience that just about anyone can grow zucchini just about anywhere; your biggest problem will not be growing the damn things but finding homes for the excess. But what I think is also interesting, and relates very well to the modern age, is one further tweak to the recipe I can add in case you are murderously inclined.
I noticed in my once-over-lightly research in Wikipedia that zucchini naturally contain a toxin called cucurbitacin. Most zucchini have had the toxins bred nearly out of them. But here’s a quote that might scare you a little:
“Pathologists found cucurbitacin in the stomach of a 79-year-old man who died in Bavaria, Germany, shortly after eating a casserole containing zucchini he had received from a neighbor. The “Chemische- und Veterinäruntersuchungsamt Stuttgart” (chemical and veterinary research authority) found cucurbitacin in a sample of the casserole the man had eaten shortly before his death. Maria Roth of that agency said that recent hot weather had likely stressed the plant, causing more toxin than usual to be present.”
If you could find a way to produce or obtain cucurbitacin, and then introduce it into a particular zucchini using yarn … that would result in an unnatural death with an apparently natural cause. There’s a nifty little mystery there, for anyone who cares to write it. I think I’ll just begin to abstain from zucchini and, most sensibly, never have anything to do with vegetable duck.